Add worktrees, per-hunk review, effort per message, regenerate, voice input

- Isolated git worktree per session (create, status, merge, discard)
- Permission card: accept file-edit hunks individually; agent learns what was rejected
- Reasoning effort per message; regenerate the last answer with another model/effort
- Voice input via the Web Speech API
- Folder-up button in the file browser; ssh, rsync and mc in the image

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Dockerfile

@@ -29,6 +29,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
         build-essential pkg-config libssl-dev cmake zlib1g-dev binutils-multiarch \
         chromium fonts-dejavu-core fonts-noto-color-emoji poppler-utils openmpt123 \
         openscad xvfb xauth \
+        openssh-client rsync mc \
     && rm -rf /var/lib/apt/lists/*
 # Language servers for diagnostics after edits (rust-analyzer/gopls/clangd can be
 # installed by agents: rustup component add rust-analyzer, go install …).

server/src/api.rs

@@ -74,6 +74,8 @@ pub fn router(app: AppState) -> Router {
         .route("/sessions/search", get(search_sessions))
         .route("/sessions/{id}/fork", post(fork_session))
         .route("/sessions/{id}/title", post(suggest_title))
+        .route("/sessions/{id}/regenerate", post(regenerate))
+        .route("/sessions/{id}/worktree", get(worktree_status).post(worktree_action))
         .route("/sessions/{id}/export", get(export_session))
         .route("/sessions/{id}", get(get_session).patch(update_session).delete(delete_session))
         .route("/sessions/{id}/prompt", post(prompt))
@@ -409,6 +411,7 @@ async fn create_session(Extension(user): Extension<User>, State(app): State<AppS
         last_usage: None,
         clean_room: body.clean_room,
         phase: None,
+        worktree: None,
     };
     let s = app.save_session(s)?;
     Ok(Json(json!(s)))
@@ -433,6 +436,88 @@ async fn search_sessions(Extension(user): Extension<User>, State(app): State<App
     Ok(Json(json!(hits)))
 }
 
+#[derive(Deserialize)]
+struct RegenerateBody {
+    /// An assistant message of the turn to redo.
+    message_id: String,
+    model: Option<String>,
+    effort: Option<String>,
+}
+
+/// Redo a turn: drop everything after the user's prompt, restore files changed
+/// since, and run again (optionally with another model / effort).
+async fn regenerate(Extension(user): Extension<User>, State(app): State<AppState>, Path(id): Path<String>, Json(b): Json<RegenerateBody>) -> ApiResult {
+    let mut s = writable(&app, &user, &id)?;
+    if app.is_busy(&id) {
+        return Err(ApiError(StatusCode::CONFLICT, "session is busy".into()));
+    }
+    let msgs = app.store.messages(&id)?;
+    let idx = msgs.iter().position(|m| m.id == b.message_id).ok_or_else(|| not_found("message"))?;
+    // The prompt of this turn: the last user message with real content before it.
+    let prompt_idx = msgs[..idx]
+        .iter()
+        .rposition(|m| matches!(m.role, crate::types::Role::User) && m.parts.iter().any(|p| matches!(p, Part::Text { .. } | Part::Image { .. })))
+        .ok_or_else(|| ApiError(StatusCode::BAD_REQUEST, "no prompt before this message".into()))?;
+    let first_dropped = msgs.get(prompt_idx + 1).ok_or_else(|| ApiError(StatusCode::BAD_REQUEST, "nothing to regenerate".into()))?;
+    if let Some(m) = b.model.filter(|m| !m.is_empty()) {
+        app.registry().resolve(&m).map_err(|e| ApiError(StatusCode::BAD_REQUEST, format!("{e:#}")))?;
+        s.model = m;
+    }
+    // Files the dropped steps changed go back to their state before.
+    let since = first_dropped.created_at;
+    let roots = app.user_roots(s.owner_id.as_deref());
+    for (path, content) in app.store.checkpoints_since(&id, since)? {
+        let p = PathBuf::from(&path);
+        if !roots.iter().any(|r| p.starts_with(r)) {
+            continue;
+        }
+        match content {
+            Some(bytes) => {
+                let _ = std::fs::write(&p, bytes);
+            }
+            None => {
+                let _ = std::fs::remove_file(&p);
+            }
+        }
+    }
+    app.store.delete_checkpoints_since(&id, since)?;
+    app.store.truncate_from(&id, &first_dropped.id)?;
+    s.last_usage = None;
+    app.save_session(s)?;
+    set_turn_effort(&app, &id, b.effort.as_deref())?;
+    runner::submit(app.clone(), id.clone(), vec![], "user").map_err(|e| ApiError(StatusCode::INTERNAL_SERVER_ERROR, format!("{e:#}")))?;
+    Ok(Json(json!({"ok": true})))
+}
+
+#[derive(Deserialize)]
+struct WorktreeBody {
+    action: String,
+}
+
+async fn worktree_status(Extension(user): Extension<User>, State(app): State<AppState>, Path(id): Path<String>) -> ApiResult {
+    let mut s = readable(&app, &user, &id)?;
+    if s.worktree.is_none() {
+        return Ok(Json(json!({"worktree": null})));
+    }
+    Ok(Json(crate::git::worktree(&app, &user, &mut s, "status").await?))
+}
+
+async fn worktree_action(Extension(user): Extension<User>, State(app): State<AppState>, Path(id): Path<String>, Json(b): Json<WorktreeBody>) -> ApiResult {
+    let mut s = writable(&app, &user, &id)?;
+    if app.is_busy(&id) && b.action != "status" {
+        return Err(ApiError(StatusCode::CONFLICT, "the session is busy – wait until the agent is done".into()));
+    }
+    let res = crate::git::worktree(&app, &user, &mut s, &b.action).await?;
+    if b.action == "remove" {
+        s.worktree = None;
+    }
+    if b.action != "status" {
+        app.save_session(s)?;
+        app.audit(Some(&user), &format!("worktree.{}", b.action), &id, "");
+    }
+    Ok(Json(res))
+}
+
 #[derive(Deserialize, Default)]
 struct TitleBody {
     model: Option<String>,
@@ -472,6 +557,7 @@ async fn fork_session(Extension(user): Extension<User>, State(app): State<AppSta
         updated_at: now,
         last_usage: None,
         phase: None,
+        worktree: None,
         ..src.clone()
     };
     let fork = app.save_session(fork)?;
@@ -569,6 +655,21 @@ struct PromptBody {
     text: String,
     #[serde(default)]
     images: Vec<ImageData>,
+    /// Reasoning effort for this turn (low, medium, high, xhigh, max).
+    effort: Option<String>,
+}
+
+const EFFORTS: &[&str] = &["low", "medium", "high", "xhigh", "max"];
+
+fn set_turn_effort(app: &App, id: &str, effort: Option<&str>) -> Result<(), ApiError> {
+    match effort.filter(|e| !e.is_empty()) {
+        Some(e) if !EFFORTS.contains(&e) => Err(ApiError(StatusCode::BAD_REQUEST, format!("invalid effort '{e}'"))),
+        Some(e) if !app.is_busy(id) => {
+            app.with_runtime(id, |r| r.effort = Some(e.to_string()));
+            Ok(())
+        }
+        _ => Ok(()),
+    }
 }
 
 async fn prompt(Extension(user): Extension<User>, State(app): State<AppState>, Path(id): Path<String>, Json(body): Json<PromptBody>) -> ApiResult {
@@ -600,6 +701,7 @@ async fn prompt(Extension(user): Extension<User>, State(app): State<AppState>, P
             }
         }
     }
+    set_turn_effort(&app, &id, body.effort.as_deref())?;
     let mut parts = vec![Part::Text { text: prompt_text }];
     for image in body.images {
         parts.push(Part::Image { image });
@@ -775,12 +877,14 @@ fn check_pending(app: &App, user: &User, id: &str) -> Result<(), ApiError> {
 struct PermissionBody {
     reply: PermissionReply,
     message: Option<String>,
+    /// Accepted diff hunks of a file edit (indices); missing = all.
+    hunks: Option<Vec<usize>>,
 }
 
 async fn reply_permission(Extension(user): Extension<User>, State(app): State<AppState>, Path(id): Path<String>, Json(body): Json<PermissionBody>) -> ApiResult {
     check_pending(&app, &user, &id)?;
     let what = app.pending_title(&id).unwrap_or_default();
-    app.reply_permission(&id, body.reply, body.message)?;
+    app.reply_permission(&id, body.reply, body.message, body.hunks)?;
     app.audit(Some(&user), &format!("permission.{}", serde_json::to_value(body.reply).ok().and_then(|v| v.as_str().map(String::from)).unwrap_or_default()), what, "");
     Ok(Json(json!({"ok": true})))
 }

server/src/app.rs

@@ -25,7 +25,7 @@ pub enum PermissionReply {
 
 struct PendingPermission {
     event: Event,
-    tx: oneshot::Sender<(PermissionReply, Option<String>)>,
+    tx: oneshot::Sender<(PermissionReply, Option<String>, Option<Vec<usize>>)>,
 }
 
 struct PendingQuestion {
@@ -41,6 +41,8 @@ pub struct Runtime {
     pub approved: HashSet<String>,
     /// The model request currently running (for clients that connect mid-step).
     pub step: Option<Value>,
+    /// Reasoning effort chosen for the current turn (overrides the model's default).
+    pub effort: Option<String>,
 }
 
 pub struct App {
@@ -436,7 +438,7 @@ impl App {
         input: Value,
         diff: Option<String>,
         cancel: CancellationToken,
-    ) -> (PermissionReply, Option<String>) {
+    ) -> (PermissionReply, Option<String>, Option<Vec<usize>>) {
         let id = crate::types::new_id();
         let event = Event::PermissionRequest {
             id: id.clone(),
@@ -451,17 +453,18 @@ impl App {
         self.permissions.lock().unwrap().insert(id.clone(), PendingPermission { event: event.clone(), tx });
         self.emit(event);
         let res = tokio::select! {
-            r = rx => r.unwrap_or((PermissionReply::Reject, None)),
-            _ = cancel.cancelled() => (PermissionReply::Reject, Some("aborted".into())),
+            r = rx => r.unwrap_or((PermissionReply::Reject, None, None)),
+            _ = cancel.cancelled() => (PermissionReply::Reject, Some("aborted".into()), None),
         };
         self.permissions.lock().unwrap().remove(&id);
         self.emit(Event::PermissionResolved { id, session_id: session_id.to_string() });
         res
     }
 
-    pub fn reply_permission(&self, id: &str, reply: PermissionReply, message: Option<String>) -> Result<()> {
+    /// `hunks`: for file edits, the indices of the diff hunks the user accepted (None = all).
+    pub fn reply_permission(&self, id: &str, reply: PermissionReply, message: Option<String>, hunks: Option<Vec<usize>>) -> Result<()> {
         let p = self.permissions.lock().unwrap().remove(id).ok_or_else(|| anyhow!("permission not pending"))?;
-        let _ = p.tx.send((reply, message));
+        let _ = p.tx.send((reply, message, hunks));
         Ok(())
     }
 }

server/src/git.rs

@@ -377,3 +377,103 @@ mod tests {
         assert!(!valid_ref("a b"));
     }
 }
+
+// --- worktrees per session -------------------------------------------------------
+
+fn wt_str<'a>(wt: &'a Value, key: &str) -> &'a str {
+    wt[key].as_str().unwrap_or("")
+}
+
+/// Create, inspect, merge or remove the session's isolated worktree.
+pub async fn worktree(app: &std::sync::Arc<App>, user: &User, session: &mut crate::types::Session, action: &str) -> Result<Value, ApiError> {
+    let spec = crate::sandbox::spec_for(app, Some(&user.id));
+    let cfg = crate::gitcreds::global_config(app, user);
+    let s = session.clone();
+    let res = SANDBOX.scope(spec, GITCONFIG.scope(cfg, worktree_inner(s, action))).await?;
+    if let Some(cwd) = res.get("cwd").and_then(|v| v.as_str()) {
+        session.cwd = cwd.to_string();
+    }
+    if res.get("worktree").is_some() {
+        session.worktree = res["worktree"].clone().as_object().map(|_| res["worktree"].clone());
+    }
+    Ok(res)
+}
+
+async fn worktree_inner(session: crate::types::Session, action: &str) -> Result<Value, ApiError> {
+    let bad = |m: &str| ApiError(StatusCode::BAD_REQUEST, m.to_string());
+    match action {
+        "create" => {
+            if session.worktree.is_some() {
+                return Err(bad("this session already has a worktree"));
+            }
+            let cwd = PathBuf::from(&session.cwd);
+            let repo = repo_root(&cwd).ok_or_else(|| bad("the session folder is not in a git repository"))?;
+            let sub = cwd.strip_prefix(&repo).map(|p| p.to_path_buf()).unwrap_or_default();
+            let short: String = session.id.chars().rev().take(8).collect::<String>().chars().rev().collect();
+            let branch = format!("codecraft/{short}");
+            let path = repo.join(".codecraft").join("worktrees").join(&short);
+            let base = git_ok(&repo, &["rev-parse", "--abbrev-ref", "HEAD"], 30).await?.trim().to_string();
+            if base == "HEAD" {
+                return Err(bad("the repository is in detached HEAD state – check out a branch first"));
+            }
+            // Keep the worktrees out of the repository's status (local only, not committed).
+            let common = git_ok(&repo, &["rev-parse", "--git-common-dir"], 30).await?.trim().to_string();
+            let common = if Path::new(&common).is_absolute() { PathBuf::from(common) } else { repo.join(common) };
+            let exclude = common.join("info").join("exclude");
+            let current = std::fs::read_to_string(&exclude).unwrap_or_default();
+            if !current.lines().any(|l| l.trim() == ".codecraft/") {
+                let _ = std::fs::create_dir_all(exclude.parent().unwrap());
+                let _ = std::fs::write(&exclude, format!("{current}{}.codecraft/\n", if current.is_empty() || current.ends_with('\n') { "" } else { "\n" }));
+            }
+            std::fs::create_dir_all(path.parent().unwrap()).map_err(|e| bad(&e.to_string()))?;
+            let p = path.display().to_string();
+            git_ok(&repo, &["worktree", "add", "-b", &branch, &p, "HEAD"], 120).await?;
+            let wt = json!({"repo": repo, "path": path, "branch": branch, "base": base, "sub": sub});
+            let cwd = if sub.as_os_str().is_empty() { path.clone() } else { path.join(&sub) };
+            Ok(json!({"ok": true, "worktree": wt, "cwd": cwd}))
+        }
+        "status" => {
+            let wt = session.worktree.clone().ok_or_else(|| bad("no worktree"))?;
+            let path = PathBuf::from(wt_str(&wt, "path"));
+            let dirty = git_ok(&path, &["status", "--porcelain"], 60).await?.lines().count();
+            let range = format!("{}..{}", wt_str(&wt, "base"), wt_str(&wt, "branch"));
+            let commits = git_ok(&path, &["log", "--oneline", &range], 60).await.unwrap_or_default();
+            let stat = git_ok(&path, &["diff", "--shortstat", wt_str(&wt, "base")], 60).await.unwrap_or_default();
+            Ok(json!({"worktree": wt, "dirty_files": dirty, "commits": commits.lines().collect::<Vec<_>>(), "diffstat": stat.trim()}))
+        }
+        "merge" => {
+            let wt = session.worktree.clone().ok_or_else(|| bad("no worktree"))?;
+            let path = PathBuf::from(wt_str(&wt, "path"));
+            let repo = PathBuf::from(wt_str(&wt, "repo"));
+            let (branch, base) = (wt_str(&wt, "branch"), wt_str(&wt, "base"));
+            // Uncommitted work in the worktree is committed first.
+            if !git_ok(&path, &["status", "--porcelain"], 60).await?.trim().is_empty() {
+                git_ok(&path, &["add", "-A"], 120).await?;
+                let msg = format!("CodeCraft: {}", if session.title.is_empty() { "session changes" } else { session.title.as_str() });
+                git_ok(&path, &["commit", "-q", "-m", &msg], 120).await?;
+            }
+            let current = git_ok(&repo, &["rev-parse", "--abbrev-ref", "HEAD"], 30).await?.trim().to_string();
+            if current != base {
+                return Err(bad(&format!("the main working copy is on '{current}', not on '{base}' – check out '{base}' first")));
+            }
+            let msg = format!("Merge {branch}{}", if session.title.is_empty() { String::new() } else { format!(": {}", session.title) });
+            let o = git(&repo, &["merge", "--no-ff", "-m", &msg, branch], 300).await?;
+            if !o.ok {
+                let _ = git(&repo, &["merge", "--abort"], 60).await;
+                return Err(ApiError(StatusCode::CONFLICT, format!("merge failed (aborted, nothing changed): {}", if o.stderr.trim().is_empty() { o.stdout.trim() } else { o.stderr.trim() })));
+            }
+            Ok(json!({"ok": true, "merged": branch, "into": base, "output": o.stdout.trim()}))
+        }
+        "remove" => {
+            let wt = session.worktree.clone().ok_or_else(|| bad("no worktree"))?;
+            let repo = PathBuf::from(wt_str(&wt, "repo"));
+            let p = wt_str(&wt, "path").to_string();
+            git_ok(&repo, &["worktree", "remove", "--force", &p], 120).await?;
+            let _ = git(&repo, &["branch", "-D", wt_str(&wt, "branch")], 60).await;
+            let sub = wt_str(&wt, "sub");
+            let cwd = if sub.is_empty() { repo.clone() } else { repo.join(sub) };
+            Ok(json!({"ok": true, "worktree": Value::Null, "cwd": if cwd.is_dir() { cwd } else { repo }}))
+        }
+        _ => Err(bad("unknown worktree action")),
+    }
+}

server/src/jobs.rs

@@ -153,6 +153,7 @@ pub async fn run(app: &Arc<App>, job: &Job, trigger: &str) -> Result<String> {
         last_usage: None,
         clean_room: None,
         phase: None,
+        worktree: None,
     };
     let session = app.save_session(session)?;
     app.store.job_started(&job.id, &session.id, now)?;

server/src/runner.rs

@@ -90,10 +90,13 @@ pub fn submit(app: Arc<App>, session_id: String, parts: Vec<Part>, source: &str)
             if source == "user" {
                 parts.extend(crate::mentions::expand(&app, &session_id, &text_only).await);
             }
+            // Empty parts: continue from the existing history (regenerate).
+            if !parts.is_empty() {
                 let msg = Message::new(Role::User, parts);
                 app.store.add_message(&session_id, &msg)?;
                 app.emit(Event::MessageAdded { session_id: session_id.clone(), message: msg });
                 maybe_generate_title(app.clone(), &session_id, &text_only);
+            }
             run_session(app.clone(), &session_id, cancel.clone(), 0).await
         }
         .await;
@@ -105,6 +108,7 @@ pub fn submit(app: Arc<App>, session_id: String, parts: Vec<Part>, source: &str)
         // stopped the agent: then they stay queued until sent explicitly.
         let leftover = app.with_runtime(&session_id, |r| {
             r.cancel = None;
+            r.effort = None;
             if cancel.is_cancelled() { Vec::new() } else { take_queue(&app, &session_id) }
         });
         app.emit(Event::SessionStatus { session_id: session_id.clone(), busy: false });
@@ -271,7 +275,10 @@ pub async fn run_session(app: Arc<App>, session_id: &str, cancel: CancellationTo
             agent.prompt = prompts::craft_prompt(clean_room);
         }
         let model_spec = agent.model.clone().unwrap_or_else(|| session.model.clone());
-        let (provider, model) = app.registry().resolve(&model_spec)?;
+        let (provider, mut model) = app.registry().resolve(&model_spec)?;
+        if let Some(effort) = app.with_runtime(session_id, |r| r.effort.clone()) {
+            model.effort = Some(effort);
+        }
 
         // Auto-compaction when the last request used most of the context window.
         if let (Some(u), Some(ctx_len)) = (&session.last_usage, model.context) {
@@ -464,6 +471,8 @@ async fn execute_call(
     };
     let name = name.as_str();
 
+    // Hunks of a file edit the user accepted in the review (None = whole change).
+    let mut partial: Option<Vec<usize>> = None;
     // Permission check. Approvals are tracked on the top-level session.
     let root = app.root_session_id(&session.id);
     let cfg = app.config();
@@ -476,7 +485,7 @@ async fn execute_call(
         }
         Decision::Ask => {
             let diff = tool.preview(&input, &ctx).await;
-            let (reply, message) = app
+            let (reply, message, hunks) = app
                 .request_permission(&session.id, name, tool.title(&input), input.clone(), diff, base.cancel.clone())
                 .await;
             match reply {
@@ -499,6 +508,12 @@ async fn execute_call(
                 }),
                 PermissionReply::Once => {}
             }
+            if let Some(sel) = hunks {
+                if sel.is_empty() {
+                    return tool_result(call_id, call_name, "The user rejected all parts of this change.".into(), true, None);
+                }
+                partial = Some(sel);
+            }
         }
         Decision::Allow => {}
     }
@@ -528,7 +543,9 @@ async fn execute_call(
     }
     let input_path = input["path"].as_str().map(String::from);
     let input_for_phase = if base.agent == "craft" { input.clone() } else { Value::Null };
-    let res = if name == "task" {
+    let res = if let (Some(sel), true) = (&partial, matches!(name, "write" | "edit")) {
+        apply_partial(&ctx, name, &input, sel).await
+    } else if name == "task" {
         // Pass depth through the agent name channel: subagents run with depth+1.
         run_task(app, &ctx, input, depth).await
     } else {
@@ -669,6 +686,7 @@ fn create_child(app: &Arc<App>, ctx: &ToolCtx, agent_name: &str, description: &s
         last_usage: None,
         clean_room: parent.clean_room,
         phase: None,
+        worktree: None,
     };
     let child = app.save_session(child)?;
     let msg = Message::new(Role::User, vec![Part::Text { text: prompt }]);
@@ -997,6 +1015,30 @@ pub async fn suggest_title(app: Arc<App>, session_id: &str, model_spec: Option<S
     Ok(title.chars().take(80).collect())
 }
 
+/// Write only the hunks of a proposed write/edit that the user accepted.
+async fn apply_partial(ctx: &ToolCtx, name: &str, input: &Value, selected: &[usize]) -> Result<tools::ToolOutput> {
+    let path = ctx.resolve(tools::arg_str(input, "path")?)?;
+    let old = tokio::fs::read_to_string(&path).await.unwrap_or_default();
+    let proposed = if name == "write" { tools::arg_str(input, "content")?.to_string() } else { tools::fs::apply_edit(&old, input)? };
+    let (result, total) = tools::fs::apply_hunks(&old, &proposed, selected);
+    let accepted = selected.iter().filter(|i| **i < total).count();
+    if let Some(dir) = path.parent() {
+        tokio::fs::create_dir_all(dir).await?;
+    }
+    tokio::fs::write(&path, &result).await?;
+    ctx.app.mark_read(&ctx.session_id, &path);
+    let rel = path.strip_prefix(&ctx.cwd).map(|p| p.display().to_string()).unwrap_or_else(|_| path.display().to_string());
+    let applied = tools::fs::unified_diff(&rel, &old, &result);
+    let rejected = tools::fs::unified_diff(&rel, &result, &proposed);
+    Ok(tools::ToolOutput::text(format!(
+        "The user reviewed your change to {rel} and applied only {accepted} of {total} hunks. \
+         The file now contains the accepted parts; the rejected parts were NOT applied – do not re-apply them unless the user asks.\n\n\
+         Rejected (what is still missing compared to your proposal):\n{}",
+        clip(&rejected, 8000)
+    ))
+    .with_meta(serde_json::json!({"diff": applied, "path": path, "partial": {"accepted": accepted, "total": total}})))
+}
+
 const PHASES: &[&str] = &["study", "specify", "build", "check", "ready"];
 
 /// Craft phase implied by a tool call (fallback when the agent does not report it).

server/src/tools/fs.rs

@@ -22,6 +22,27 @@ fn image_type(path: &Path) -> Option<&'static str> {
     }
 }
 
+/// Apply only the selected hunks (indices of the 3-line-context groups, as in
+/// `unified_diff`) of the change old -> new. Returns (result, total hunks).
+pub fn apply_hunks(old: &str, new: &str, selected: &[usize]) -> (String, usize) {
+    let diff = similar::TextDiff::from_lines(old, new);
+    let groups = diff.grouped_ops(3);
+    let total = groups.len();
+    let mut out = String::new();
+    for op in diff.ops() {
+        let in_selected = op.tag() != similar::DiffTag::Equal && groups.iter().enumerate().any(|(i, g)| selected.contains(&i) && g.contains(op));
+        let lines: Vec<&str> = if in_selected {
+            diff.new_slices()[op.new_range()].to_vec()
+        } else {
+            diff.old_slices()[op.old_range()].to_vec()
+        };
+        for l in lines {
+            out.push_str(l);
+        }
+    }
+    (out, total)
+}
+
 pub fn unified_diff(path: &str, old: &str, new: &str) -> String {
     similar::TextDiff::from_lines(old, new)
         .unified_diff()
@@ -235,7 +256,7 @@ impl Tool for Edit {
     }
 }
 
-fn apply_edit(old: &str, input: &Value) -> Result<String> {
+pub fn apply_edit(old: &str, input: &Value) -> Result<String> {
     let from = arg_str(input, "old_string")?;
     let to = arg_str(input, "new_string")?;
     if from.is_empty() {
@@ -484,3 +505,19 @@ mod tests {
         assert!(apply_edit("xyz", &input).is_err());
     }
 }
+
+#[cfg(test)]
+mod hunk_tests {
+    #[test]
+    fn partial_apply() {
+        let old: String = (1..=30).map(|i| format!("line {i}\n")).collect();
+        let new = old.replace("line 2\n", "line TWO\n").replace("line 25\n", "line 25\nextra\n");
+        let (only_first, total) = super::apply_hunks(&old, &new, &[0]);
+        assert_eq!(total, 2);
+        assert!(only_first.contains("line TWO") && !only_first.contains("extra"));
+        let (only_second, _) = super::apply_hunks(&old, &new, &[1]);
+        assert!(!only_second.contains("line TWO") && only_second.contains("extra"));
+        assert_eq!(super::apply_hunks(&old, &new, &[0, 1]).0, new);
+        assert_eq!(super::apply_hunks(&old, &new, &[]).0, old);
+    }
+}

server/src/types.rs

@@ -130,6 +130,9 @@ pub struct Session {
     /// Craft workflow phase reported by the agent (study, specify, build, check, ready).
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub phase: Option<String>,
+    /// Isolated git worktree of this session: {repo, path, branch, base}.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub worktree: Option<Value>,
 }
 
 impl Session {

web/src/components/ChatView.tsx

@@ -12,6 +12,8 @@ import { useReasoningMode } from "../prefs";
 import { Composer } from "./Composer";
 import { ShareDialog } from "./ShareDialog";
 import { RenameDialog } from "./RenameDialog";
+import { RegenerateButton } from "./Regenerate";
+import { WorktreeChip } from "./WorktreeChip";
 import { QueueList } from "./QueueList";
 import { BudgetChip } from "./Budget";
 import { PermissionCard, QuestionCard } from "./Interaction";
@@ -215,14 +217,14 @@ export function ChatView({ sessionId, onMenu }: { sessionId: string; onMenu: ()
     }
   };
 
-  const send = async (raw: string, images: ImageData[]) => {
+  const send = async (raw: string, images: ImageData[], effort?: string) => {
     const txt = raw.trim();
     if (txt === "/new") {
       setText("");
       return navigate("/new");
     }
     try {
-      await post(`/sessions/${sessionId}/prompt`, { text: txt, images });
+      await post(`/sessions/${sessionId}/prompt`, { text: txt, images, effort: effort || undefined });
       setText("");
       follow(true);
     } catch (e: any) {
@@ -230,6 +232,7 @@ export function ChatView({ sessionId, onMenu }: { sessionId: string; onMenu: ()
     }
   };
 
+  const lastAssistantIdx = messages.reduce((acc, m, i) => (m.role === "assistant" ? i : acc), -1);
   const [rewinding, setRewinding] = useState<Message>();
   const rewind = (m: Message) => setRewinding(m);
   const rewindDone = async () => {
@@ -296,6 +299,7 @@ export function ChatView({ sessionId, onMenu }: { sessionId: string; onMenu: ()
             {fmtCost(stats.total.cost, stats.currency)}
           </button>
         )}
+        <WorktreeChip session={session} busy={busy} />
         <ShellsChip sessionId={sessionId} busy={busy} />
         {isAdmin && <BudgetChip />}
         {session.permission_mode === "bypass" && <span className="chip warn">{t("permissionMode.bypass")}</span>}
@@ -323,16 +327,33 @@ export function ChatView({ sessionId, onMenu }: { sessionId: string; onMenu: ()
               </button>
             )}
             <details className="menu-pop">
-              <summary className="small ghost" title={t("chat.export")}>
-                <Icon name="download" />
+              <summary className="small ghost" title={t("chat.more")} aria-label={t("chat.more")}>
+                <Icon name="more" />
               </summary>
               <div className="menu-pop-body">
                 <a href={`/api/sessions/${sessionId}/export?format=md`} download>
-                  {t("chat.exportMd")}
+                  <Icon name="download" /> {t("chat.exportMd")}
                 </a>
                 <a href={`/api/sessions/${sessionId}/export?format=json`} download>
-                  {t("chat.exportJson")}
+                  <Icon name="download" /> {t("chat.exportJson")}
                 </a>
+                {!session.parent_id && !session.worktree && (
+                  <a
+                    href="#"
+                    onClick={async (e) => {
+                      e.preventDefault();
+                      (e.currentTarget.closest("details") as HTMLDetailsElement).open = false;
+                      try {
+                        await post(`/sessions/${sessionId}/worktree`, { action: "create" });
+                        toast(t("worktree.created"), "success");
+                      } catch (err: any) {
+                        toast(err.message);
+                      }
+                    }}
+                  >
+                    <Icon name="fork" /> {t("worktree.create")}
+                  </a>
+                )}
               </div>
             </details>
             <button className="small ghost" onClick={() => post(`/sessions/${sessionId}/compact`).catch((e) => toast(e.message))} disabled={busy} title={t("command.compact")}>
@@ -366,11 +387,13 @@ export function ChatView({ sessionId, onMenu }: { sessionId: string; onMenu: ()
         <div className="chat">
           {showStats && <UsageOverlay session={session} onClose={() => setShowStats(false)} />}
           {messages.length === 0 && !draft && <div className="empty">{t("chat.empty")}</div>}
-          {messages.map((m) => {
+          {messages.map((m, idx) => {
             if (m.role === "assistant") {
+              const lastAnswer = idx === lastAssistantIdx && !busy && !readOnly && !session.parent_id;
               return (
                 <div key={m.id} className="msg">
                   <AssistantParts parts={m.parts} results={results} running={busy} live={false} baseDir={session.cwd} />
+                  {lastAnswer && <RegenerateButton sessionId={sessionId} messageId={m.id} model={session.model} />}
                 </div>
               );
             }

web/src/components/Composer.tsx

@@ -2,10 +2,12 @@ import { Icon } from "./Icon";
 import { formatSize } from "./FileFigure";
 import { uploadFile } from "../api";
 import { useEffect, useMemo, useRef, useState } from "react";
-import { useAgents, useFetch } from "../hooks";
+import { useAgents, useFetch, useModels } from "../hooks";
 import { useT, type Key } from "../i18n";
 import type { ImageData, Session } from "../types";
 import { ModelSelect } from "./ModelSelect";
+import { EffortSelect } from "./Regenerate";
+import { VoiceButton } from "./Voice";
 import { confirmDialog, promptDialog, toast } from "../dialogs";
 
 interface Suggestion {
@@ -49,7 +51,7 @@ export function Composer({
   busy: boolean;
   text: string;
   setText: (s: string) => void;
-  onSend: (text: string, images: ImageData[]) => void;
+  onSend: (text: string, images: ImageData[], effort?: string) => void;
   onAbort: () => void;
   onUpdate: (patch: Partial<Session>) => void;
 }) {
@@ -60,6 +62,12 @@ export function Composer({
   const [files, setFiles] = useState<{ name: string; path: string; size: number }[]>([]);
   const [uploading, setUploading] = useState(0);
   const [active, setActive] = useState(0);
+  // Reasoning effort for the next message only ("" = model default).
+  const [effort, setEffort] = useState("");
+  const [interim, setInterim] = useState("");
+  const models = useModels();
+  const [prov, ...mid] = session.model.split("/");
+  const reasoning = !!models.find((p) => p.provider === prov)?.models.find((m) => m.id === mid.join("/"))?.reasoning;
   // @file mentions: token before the caret and matching files.
   const [mention, setMention] = useState<{ start: number; end: number; q: string }>();
   const [mentionHits, setMentionHits] = useState<{ rel: string; is_dir: boolean }[]>([]);
@@ -130,7 +138,8 @@ export function Composer({
     if ((!text.trim() && images.length === 0 && files.length === 0) || uploading > 0) return;
     // Files are referenced by path; the agent reads them with its tools.
     const refs = files.length ? `\n\n${t("composer.attachedFiles")}\n${files.map((f) => `- ${f.path} (${formatSize(f.size)})`).join("\n")}` : "";
-    onSend(`${text}${refs}`, images);
+    onSend(`${text}${refs}`, images, effort);
+    setEffort("");
     setImages([]);
     setFiles([]);
   };
@@ -258,7 +267,7 @@ export function Composer({
           ref={ref}
           rows={1}
           value={text}
-          placeholder={busy ? t("composer.placeholderBusy") : t("composer.placeholder")}
+          placeholder={interim ? `${interim} …` : busy ? t("composer.placeholderBusy") : t("composer.placeholder")}
           onChange={(e) => {
             setText(e.target.value);
             setActive(0);
@@ -312,6 +321,8 @@ export function Composer({
             <option value="bypass">{t("permissionMode.bypass")}</option>
           </select>
           <ModelSelect value={session.model} onChange={(m) => onUpdate({ model: m })} title={t("composer.model")} />
+          {reasoning && <EffortSelect value={effort} onChange={setEffort} compact />}
+          <VoiceButton onText={(d) => setText(text ? `${text.replace(/\s+$/, "")} ${d}` : d)} onInterim={setInterim} />
           <label className="ghost" style={{ cursor: "pointer", padding: "3px 6px" }} title={t("composer.attach")}>
             <Icon name="clip" />
             <input type="file" multiple hidden onChange={(e) => e.target.files && (addFiles(e.target.files), (e.target.value = ""))} />

web/src/components/Diff.tsx

@@ -17,3 +17,43 @@ export function Diff({ diff }: { diff: string }) {
     </div>
   );
 }
+
+/** Split a unified diff into its file header and hunks (at "@@" lines). */
+export function splitHunks(diff: string): { header: string[]; hunks: string[][] } {
+  const lines = diff.replace(/\n+$/, "").split("\n");
+  const header: string[] = [];
+  const hunks: string[][] = [];
+  for (const l of lines) {
+    if (l.startsWith("@@")) hunks.push([l]);
+    else if (hunks.length) hunks[hunks.length - 1].push(l);
+    else header.push(l);
+  }
+  return { header, hunks };
+}
+
+/** Diff with a checkbox per hunk (review a change piece by piece). */
+export function HunkDiff({ diff, selected, onToggle }: { diff: string; selected: boolean[]; onToggle: (i: number) => void }) {
+  const { header, hunks } = splitHunks(diff);
+  return (
+    <div className="diff hunk-diff">
+      {header.map((l, i) => (
+        <div key={`h${i}`} className="meta">
+          {l}
+        </div>
+      ))}
+      {hunks.map((h, i) => (
+        <div key={i} className={`hunk-block ${selected[i] ? "" : "off"}`}>
+          <label className="hunk-head">
+            <input type="checkbox" checked={!!selected[i]} onChange={() => onToggle(i)} />
+            <span>{h[0]}</span>
+          </label>
+          {h.slice(1).map((l, j) => (
+            <div key={j} className={l.startsWith("+") ? "add" : l.startsWith("-") ? "del" : ""}>
+              {l || " "}
+            </div>
+          ))}
+        </div>
+      ))}
+    </div>
+  );
+}

web/src/components/Files.tsx

@@ -268,6 +268,15 @@ export function Files({ onMenu }: { onMenu: () => void }) {
         </button>
       </div>
       <div className="crumbs">
+        <button
+          className="small ghost crumbs-up"
+          disabled={!listing?.parent}
+          onClick={() => listing?.parent && void confirmDiscard().then((ok): unknown => ok && load(listing.parent!))}
+          title={t("files.up")}
+          aria-label={t("files.up")}
+        >
+          <Icon name="folder-up" />
+        </button>
         {crumbs.map((c, i) => {
           const path = i === 0 ? c : `${crumbs[0]}/${crumbs.slice(1, i + 1).join("/")}`;
           return (

web/src/components/Icon.tsx

@@ -193,6 +193,12 @@ const P: Record<string, ReactNode> = {
   ),
   dot: <circle cx="12" cy="12" r="4.5" className="fill" />,
   plus: <path d="M12 5v14M5 12h14" />,
+  mic: (
+    <>
+      <rect x="9" y="3" width="6" height="11" rx="3" />
+      <path d="M5.5 11a6.5 6.5 0 0 0 13 0M12 17.5V21M9 21h6" />
+    </>
+  ),
   clock: (
     <>
       <circle cx="12" cy="12" r="8.5" />

web/src/components/Interaction.tsx

@@ -5,7 +5,7 @@ import { useT } from "../i18n";
 import { navigate } from "../router";
 import { useStore } from "../store";
 import type { PermissionRequest, QuestionRequest } from "../types";
-import { Diff } from "./Diff";
+import { Diff, HunkDiff, splitHunks } from "./Diff";
 
 function SubagentHint({ sessionId, currentId }: { sessionId: string; currentId: string }) {
   const t = useT();
@@ -25,11 +25,17 @@ export function PermissionCard({ req, currentId }: { req: PermissionRequest; cur
   const t = useT();
   const [feedback, setFeedback] = useState("");
   const [busy, setBusy] = useState(false);
+  // File edits with several hunks can be accepted piece by piece.
+  const hunkCount = req.diff && (req.tool === "edit" || req.tool === "write") ? splitHunks(req.diff).hunks.length : 0;
+  const [selected, setSelected] = useState<boolean[]>(() => Array(hunkCount).fill(true));
+  const chosen = selected.filter(Boolean).length;
+  const partial = hunkCount > 1 && chosen < hunkCount;
 
   const reply = async (r: "once" | "always" | "reject") => {
     setBusy(true);
     try {
-      await post(`/permissions/${req.id}`, { reply: r, message: r === "reject" ? feedback : undefined });
+      const hunks = r === "once" && partial ? selected.flatMap((on, i) => (on ? [i] : [])) : undefined;
+      await post(`/permissions/${req.id}`, { reply: r, message: r === "reject" || partial ? feedback || undefined : undefined, hunks });
     } finally {
       setBusy(false);
     }
@@ -49,7 +55,12 @@ export function PermissionCard({ req, currentId }: { req: PermissionRequest; cur
       <SubagentHint sessionId={req.session_id} currentId={currentId} />
       <div style={{ margin: "6px 0" }}>{req.title}</div>
       {command && <pre className="mono" style={{ whiteSpace: "pre-wrap", margin: "6px 0" }}>$ {command}</pre>}
-      {req.diff ? (
+      {req.diff && hunkCount > 1 ? (
+        <>
+          <div className="hint">{t("permission.hunksHint", { n: hunkCount })}</div>
+          <HunkDiff diff={req.diff} selected={selected} onToggle={(i) => setSelected((s) => s.map((v, j) => (j === i ? !v : v)))} />
+        </>
+      ) : req.diff ? (
         <Diff diff={req.diff} />
       ) : (
         !command && (
@@ -69,10 +80,10 @@ export function PermissionCard({ req, currentId }: { req: PermissionRequest; cur
         onKeyDown={(e) => e.key === "Enter" && reply("reject")}
       />
       <div className="actions">
-        <button className="primary" disabled={busy} onClick={() => reply("once")} autoFocus>
-          {t("permission.allowOnce")}
+        <button className="primary" disabled={busy || (hunkCount > 1 && chosen === 0)} onClick={() => reply("once")} autoFocus>
+          {partial ? t("permission.applySelected", { k: chosen, n: hunkCount }) : t("permission.allowOnce")}
         </button>
-        <button disabled={busy} onClick={() => reply("always")}>
+        <button disabled={busy || partial} onClick={() => reply("always")}>
           {alwaysLabel}
         </button>
         <button className="danger" disabled={busy} onClick={() => reply("reject")}>

web/src/components/NewSession.tsx

@@ -169,6 +169,7 @@ export function NewSession({ onMenu, onCreated }: { onMenu: () => void; onCreate
   // Folder: a new one (name) inside a root, or an existing one (picked).
   const [folderMode, setFolderMode] = useState<"new" | "existing" | "git">("new");
   const [repoUrl, setRepoUrl] = useState("");
+  const [isolated, setIsolated] = useState(false);
   // Original software (zip, tar.gz, installer …) for the recreate workflow, uploaded in chunks.
   const [originals, setOriginals] = useState<File[]>([]);
   const [progress, setProgress] = useState<Record<string, number>>({});
@@ -323,6 +324,10 @@ export function NewSession({ onMenu, onCreated }: { onMenu: () => void; onCreate
         agent: task === "cad" ? "build" : task,
         clean_room: isCraft ? !deep : undefined,
       });
+      if (isolated && folderMode !== "new") {
+        setCreating(t("worktree.creating"));
+        await post(`/sessions/${s.id}/worktree`, { action: "create" });
+      }
       const msgs = prompts(uploaded).filter((m) => m.trim());
       for (const [i, m] of msgs.entries()) await post(`/sessions/${s.id}/prompt`, { text: m, images: i === 0 ? images : [] });
       onCreated(s.id);
@@ -547,6 +552,15 @@ export function NewSession({ onMenu, onCreated }: { onMenu: () => void; onCreate
                 </div>
               )}
               {folderMode === "existing" && <FolderPicker path={picked} onPick={setPicked} />}
+              {folderMode !== "new" && (
+                <label className="wiz-check-row">
+                  <input type="checkbox" checked={isolated} onChange={(e) => setIsolated(e.target.checked)} />
+                  <span>
+                    <b>{t("worktree.isolate")}</b>
+                    <span className="hint"> – {t("worktree.isolateHint")}</span>
+                  </span>
+                </label>
+              )}
               {error && <div className="notice err">{error}</div>}
               <div className="wiz-start-row">
                 <button className="primary wiz-start" disabled={!canStart} onClick={create}>

web/src/components/Regenerate.tsx

@@ -0,0 +1,62 @@
+import { useState } from "react";
+import { post } from "../api";
+import { useT } from "../i18n";
+import { toast } from "../dialogs";
+import { Icon } from "./Icon";
+import { ModelSelect } from "./ModelSelect";
+
+export const EFFORTS = ["low", "medium", "high", "max"] as const;
+
+/** Effort choice for one turn ("" = the model's default). */
+export function EffortSelect({ value, onChange, compact }: { value: string; onChange: (v: string) => void; compact?: boolean }) {
+  const t = useT();
+  return (
+    <select className={compact ? "effort-select" : ""} value={value} onChange={(e) => onChange(e.target.value)} title={t("effort.title")} aria-label={t("effort.title")}>
+      <option value="">{compact ? t("effort.autoShort") : t("effort.auto")}</option>
+      {EFFORTS.map((e) => (
+        <option key={e} value={e}>
+          {t(`effort.${e}` as any)}
+        </option>
+      ))}
+    </select>
+  );
+}
+
+/** Redo the last turn, optionally with another model and effort. */
+export function RegenerateButton({ sessionId, messageId, model }: { sessionId: string; messageId: string; model: string }) {
+  const t = useT();
+  const [open, setOpen] = useState(false);
+  const [m, setM] = useState(model);
+  const [effort, setEffort] = useState("");
+  const [busy, setBusy] = useState(false);
+  const go = async () => {
+    setBusy(true);
+    try {
+      await post(`/sessions/${sessionId}/regenerate`, { message_id: messageId, model: m !== model ? m : undefined, effort: effort || undefined });
+      setOpen(false);
+    } catch (e: any) {
+      toast(e.message);
+    } finally {
+      setBusy(false);
+    }
+  };
+  return (
+    <div className="regen">
+      <button className="small ghost" onClick={() => setOpen(!open)} title={t("regen.title")}>
+        <Icon name="refresh" /> {t("regen.button")}
+      </button>
+      {open && (
+        <div className="regen-panel">
+          <div className="hint">{t("regen.hint")}</div>
+          <div className="row" style={{ gap: 6, flexWrap: "wrap" }}>
+            <ModelSelect value={m} onChange={setM} />
+            <EffortSelect value={effort} onChange={setEffort} />
+            <button className="small primary" disabled={busy} onClick={go}>
+              <Icon name="refresh" /> {t("regen.go")}
+            </button>
+          </div>
+        </div>
+      )}
+    </div>
+  );
+}

web/src/components/Voice.tsx

@@ -0,0 +1,68 @@
+import { useEffect, useRef, useState } from "react";
+import { getLang, useT } from "../i18n";
+import { toast } from "../dialogs";
+import { Icon } from "./Icon";
+
+/* Web Speech API (Chrome/Edge/Safari; Firefox has none). */
+type Recognition = {
+  lang: string;
+  continuous: boolean;
+  interimResults: boolean;
+  start(): void;
+  stop(): void;
+  onresult: ((e: any) => void) | null;
+  onend: (() => void) | null;
+  onerror: ((e: any) => void) | null;
+};
+const Impl: (new () => Recognition) | undefined = (window as any).SpeechRecognition ?? (window as any).webkitSpeechRecognition;
+
+export const voiceSupported = () => !!Impl;
+
+const LOCALES: Record<string, string> = { de: "de-DE", en: "en-US" };
+
+/** Microphone button: dictated text is appended to the message. */
+export function VoiceButton({ onText, onInterim }: { onText: (text: string) => void; onInterim: (text: string) => void }) {
+  const t = useT();
+  const [listening, setListening] = useState(false);
+  const rec = useRef<Recognition | null>(null);
+
+  useEffect(() => () => rec.current?.stop(), []);
+  if (!Impl) return null;
+
+  const toggle = () => {
+    if (listening) {
+      rec.current?.stop();
+      return;
+    }
+    const r = new Impl!();
+    r.lang = LOCALES[getLang()] ?? navigator.language;
+    r.continuous = true;
+    r.interimResults = true;
+    r.onresult = (e: any) => {
+      let interim = "";
+      for (let i = e.resultIndex; i < e.results.length; i++) {
+        const res = e.results[i];
+        if (res.isFinal) onText(res[0].transcript.trim());
+        else interim += res[0].transcript;
+      }
+      onInterim(interim);
+    };
+    r.onerror = (e: any) => {
+      if (e.error === "not-allowed" || e.error === "service-not-allowed") toast(t("voice.denied"));
+      else if (e.error !== "no-speech" && e.error !== "aborted") toast(`${t("voice.error")}: ${e.error}`);
+    };
+    r.onend = () => {
+      setListening(false);
+      onInterim("");
+    };
+    rec.current = r;
+    r.start();
+    setListening(true);
+  };
+
+  return (
+    <button type="button" className={`ghost small voice-btn ${listening ? "on" : ""}`} onClick={toggle} title={t(listening ? "voice.stop" : "voice.start")} aria-label={t(listening ? "voice.stop" : "voice.start")} aria-pressed={listening}>
+      <Icon name="mic" />
+    </button>
+  );
+}

web/src/components/WorktreeChip.tsx

@@ -0,0 +1,84 @@
+import { useEffect, useState } from "react";
+import { get, post } from "../api";
+import { useT } from "../i18n";
+import { confirmDialog, toast } from "../dialogs";
+import { Icon } from "./Icon";
+import { Spinner } from "./Activity";
+import type { Session } from "../types";
+
+interface WtStatus {
+  worktree: { repo: string; path: string; branch: string; base: string } | null;
+  dirty_files?: number;
+  commits?: string[];
+  diffstat?: string;
+}
+
+/** Chip + panel for a session working in an isolated git worktree. */
+export function WorktreeChip({ session, busy }: { session: Session; busy: boolean }) {
+  const t = useT();
+  const wt = session.worktree as WtStatus["worktree"] | undefined;
+  const [open, setOpen] = useState(false);
+  const [status, setStatus] = useState<WtStatus>();
+  const [working, setWorking] = useState<string>();
+
+  useEffect(() => {
+    if (!open) return;
+    get<WtStatus>(`/sessions/${session.id}/worktree`)
+      .then(setStatus)
+      .catch((e) => toast(e.message));
+  }, [open, session.id, busy]);
+
+  if (!wt) return null;
+
+  const act = async (action: "merge" | "remove") => {
+    const msg = action === "merge" ? t("worktree.mergeConfirm", { branch: wt.branch, base: wt.base }) : t("worktree.removeConfirm", { branch: wt.branch });
+    if (!(await confirmDialog({ message: msg, danger: action === "remove" }))) return;
+    setWorking(action);
+    try {
+      await post(`/sessions/${session.id}/worktree`, { action });
+      toast(t(action === "merge" ? "worktree.merged" : "worktree.removed", { base: wt.base }), "success");
+      if (action === "merge") setStatus(await get<WtStatus>(`/sessions/${session.id}/worktree`));
+      else setOpen(false);
+    } catch (e: any) {
+      toast(e.message);
+    } finally {
+      setWorking(undefined);
+    }
+  };
+
+  return (
+    <span className="wt-wrap">
+      <button className="chip wt-chip" onClick={() => setOpen(!open)} title={t("worktree.title")}>
+        <Icon name="fork" /> {wt.branch}
+      </button>
+      {open && (
+        <div className="menu-pop-body wt-panel">
+          <div className="hint">{t("worktree.hint", { base: wt.base })}</div>
+          {!status ? (
+            <Spinner small />
+          ) : (
+            <>
+              <div className="wt-stats">
+                <span>{t("worktree.dirty", { n: status.dirty_files ?? 0 })}</span>
+                <span>{t("worktree.commits", { n: status.commits?.length ?? 0 })}</span>
+                {status.diffstat && <span className="mono">{status.diffstat}</span>}
+              </div>
+              {!!status.commits?.length && (
+                <pre className="wt-log">{status.commits.slice(0, 8).join("\n")}</pre>
+              )}
+            </>
+          )}
+          <div className="row" style={{ gap: 6, marginTop: 8 }}>
+            <button className="small primary" disabled={busy || !!working} onClick={() => act("merge")}>
+              {working === "merge" ? <Spinner small /> : <Icon name="check" />} {t("worktree.merge", { base: wt.base })}
+            </button>
+            <button className="small danger" disabled={busy || !!working} onClick={() => act("remove")}>
+              <Icon name="trash" /> {t("worktree.remove")}
+            </button>
+          </div>
+          {busy && <div className="hint">{t("worktree.busy")}</div>}
+        </div>
+      )}
+    </span>
+  );
+}

web/src/i18n/de.ts

@@ -335,6 +335,41 @@ export const de: Messages = {
   "jobs.status.done": "fertig",
   "jobs.status.timeout": "Zeitlimit",
   "jobs.status.error": "Fehler",
+  "chat.more": "Mehr",
+  "worktree.title": "Isolierter Git-Worktree",
+  "worktree.hint": "Der Agent arbeitet auf einem eigenen Branch; deine Arbeitskopie auf „{base}“ bleibt unberührt, bis du mergst.",
+  "worktree.dirty": "{n} nicht committete Dateien",
+  "worktree.commits": "{n} Commits",
+  "worktree.merge": "In {base} mergen",
+  "worktree.remove": "Verwerfen",
+  "worktree.mergeConfirm": "Offene Änderungen committen und {branch} in {base} mergen?",
+  "worktree.removeConfirm": "Worktree und Branch {branch} verwerfen? Nicht gemergte Änderungen gehen verloren.",
+  "worktree.merged": "In {base} gemergt",
+  "worktree.removed": "Worktree verworfen",
+  "worktree.created": "Die Session arbeitet jetzt in einem eigenen Worktree",
+  "worktree.create": "Isolierter Worktree",
+  "worktree.busy": "Warte, bis der Agent fertig ist.",
+  "worktree.isolate": "In einem isolierten Git-Worktree arbeiten",
+  "worktree.isolateHint": "eigener Branch, am Ende mergen",
+  "worktree.creating": "Worktree wird angelegt…",
+  "files.up": "Einen Ordner nach oben",
+  "permission.hunksHint": "{n} Änderungen – entferne den Haken bei denen, die du nicht willst.",
+  "permission.applySelected": "Auswahl übernehmen ({k}/{n})",
+  "effort.title": "Denkaufwand für diese Nachricht",
+  "effort.auto": "Aufwand: Modell-Standard",
+  "effort.autoShort": "Aufwand: auto",
+  "effort.low": "Aufwand: niedrig",
+  "effort.medium": "Aufwand: mittel",
+  "effort.high": "Aufwand: hoch",
+  "effort.max": "Aufwand: maximal",
+  "regen.button": "Neu generieren",
+  "regen.title": "Diese Antwort neu erzeugen",
+  "regen.hint": "Entfernt diese Antwort (und stellt dabei geänderte Dateien wieder her) und führt deine letzte Nachricht erneut aus – mit dem hier gewählten Modell und Aufwand.",
+  "regen.go": "Neu generieren",
+  "voice.start": "Diktieren (Spracherkennung deines Browsers)",
+  "voice.stop": "Diktat beenden",
+  "voice.denied": "Mikrofonzugriff verweigert – in den Browser-Einstellungen erlauben.",
+  "voice.error": "Spracherkennung fehlgeschlagen",
   "new.title": "Neue Session",
   "new.directory": "Projektverzeichnis",
   "new.up": "Hoch",

web/src/i18n/en.ts

@@ -334,6 +334,41 @@ export const en = {
   "jobs.status.done": "done",
   "jobs.status.timeout": "timed out",
   "jobs.status.error": "error",
+  "chat.more": "More",
+  "worktree.title": "Isolated git worktree",
+  "worktree.hint": "The agent works on its own branch; your working copy on “{base}” stays untouched until you merge.",
+  "worktree.dirty": "{n} uncommitted files",
+  "worktree.commits": "{n} commits",
+  "worktree.merge": "Merge into {base}",
+  "worktree.remove": "Discard",
+  "worktree.mergeConfirm": "Commit open changes and merge {branch} into {base}?",
+  "worktree.removeConfirm": "Discard the worktree and branch {branch}? Unmerged changes are lost.",
+  "worktree.merged": "Merged into {base}",
+  "worktree.removed": "Worktree discarded",
+  "worktree.created": "The session now works in its own worktree",
+  "worktree.create": "Isolated worktree",
+  "worktree.busy": "Wait until the agent is done.",
+  "worktree.isolate": "Work in an isolated git worktree",
+  "worktree.isolateHint": "own branch, merge when done",
+  "worktree.creating": "Creating worktree…",
+  "files.up": "One folder up",
+  "permission.hunksHint": "{n} changes – untick the ones you don't want.",
+  "permission.applySelected": "Apply selected ({k}/{n})",
+  "effort.title": "Thinking effort for this message",
+  "effort.auto": "Effort: model default",
+  "effort.autoShort": "Effort: auto",
+  "effort.low": "Effort: low",
+  "effort.medium": "Effort: medium",
+  "effort.high": "Effort: high",
+  "effort.max": "Effort: max",
+  "regen.button": "Regenerate",
+  "regen.title": "Redo this answer",
+  "regen.hint": "Removes this answer (and restores files it changed), then runs your last message again – with the model and effort chosen here.",
+  "regen.go": "Regenerate",
+  "voice.start": "Dictate (speech recognition of your browser)",
+  "voice.stop": "Stop dictation",
+  "voice.denied": "Microphone access was denied – allow it in the browser settings.",
+  "voice.error": "Speech recognition failed",
   "new.title": "New session",
   "new.directory": "Project directory",
   "new.up": "Up",

web/src/styles.css

@@ -1555,6 +1555,18 @@ a.button.small {
   font-size: 12.5px;
   color: var(--muted);
   word-break: break-all;
+  display: flex;
+  align-items: center;
+  flex-wrap: wrap;
+  gap: 2px;
+}
+.crumbs-up {
+  margin-right: 6px;
+  padding: 3px 8px;
+}
+.crumbs-up .icon {
+  width: 18px;
+  height: 18px;
 }
 .entries {
   flex: 1;
@@ -2942,3 +2954,89 @@ button.danger-solid {
 .chip.ok {
   color: var(--green);
 }
+
+/* --- worktree ------------------------------------------------------------------- */
+.wt-wrap {
+  position: relative;
+}
+.wt-chip {
+  border: 1px solid var(--accent);
+  color: var(--accent);
+  cursor: pointer;
+}
+.wt-panel {
+  width: 340px;
+  padding: 12px;
+  gap: 6px;
+}
+.wt-stats {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 10px;
+  font-size: 13px;
+}
+.wt-log {
+  font-size: 12px;
+  background: var(--bg0);
+  padding: 6px 8px;
+  border-radius: 6px;
+  max-height: 140px;
+  overflow: auto;
+  margin: 0;
+}
+.menu-pop-body a .icon {
+  margin-right: 6px;
+}
+.wiz-check-row {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  cursor: pointer;
+}
+
+/* --- per-hunk review ----------------------------------------------------------- */
+.hunk-block {
+  border-top: 1px dashed var(--bg3);
+}
+.hunk-block.off > div {
+  opacity: 0.35;
+  text-decoration: line-through;
+}
+.hunk-head {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  cursor: pointer;
+  color: var(--blue);
+  background: var(--bg1);
+  padding: 2px 6px;
+}
+
+/* --- regenerate / effort --------------------------------------------------------- */
+.regen {
+  margin-top: 6px;
+}
+.regen > button {
+  opacity: 0.7;
+}
+.regen > button:hover {
+  opacity: 1;
+}
+.regen-panel {
+  margin-top: 6px;
+  padding: 10px;
+  border: 1px solid var(--bg3);
+  border-radius: var(--radius);
+  background: var(--bg1);
+  display: flex;
+  flex-direction: column;
+  gap: 8px;
+}
+.effort-select {
+  max-width: 150px;
+}
+
+.voice-btn.on {
+  color: var(--red);
+  animation: glow 1.2s ease-in-out infinite;
+}

web/src/types.ts

@@ -60,6 +60,8 @@ export interface Session {
   clean_room?: boolean | null;
   /** Craft workflow phase reported by the agent. */
   phase?: string;
+  /** Isolated git worktree of the session. */
+  worktree?: { repo: string; path: string; branch: string; base: string; sub?: string } | null;
   /** Listed because it was shared with the current user. */
   shared?: boolean;
 }