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>

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)?;