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>

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>
+  );
+}