feat: AI commit messages, change tree, router behavesAs, sidebar times (v2.2.0)

- Changes panel: Files and Changes merged into one panel; the overview's
  groups drawn as a folder tree (compacted chains, file counts, fold,
  stage/unstage a whole folder)
- AI-suggested commit message for what is staged
  (POST /api/lanes/:id/git/commit-message, claude -p --safe-mode, haiku)
- AI Router: optional "Behaves as" Claude model id, written as
  modelPicker options into the router's --settings file (issue #56)
- Sidebar: session rows show last activity, live rows their start time;
  a closed Terminal row can be removed (DELETE /api/run/history/:id)
- Every pane's CLI starts only once a client is attached; claude panes
  no longer forced inline; tmux scrollbar one column wide
- Update notifier: "Check for updates" reopens a closed notice

openapi.yaml

@@ -3,7 +3,7 @@
 openapi: 3.0.3
 info:
   title: Agent Dashboard for Claude Code API
-  version: 2.1.0
+  version: 2.2.0
   description: HTTP API for real-time Claude Code session monitoring, agent lifecycle tracking, analytics, pricing, hooks ingestion, and workflow intelligence.
   contact:
     name: Nguyễn Ngọc Trí Vĩ
@@ -10630,6 +10630,50 @@ paths:
                 error:
                   code: EBADORIGIN
                   message: cross-origin requests are not allowed
+  /api/run/history/{id}:
+    delete:
+      tags:
+        - Run
+      summary: Forget a closed Terminal tab
+      description: Deletes one `dashboard_runs` row whose tool is `shell` — a closed Terminal tab, which has no session — so it leaves the sidebar's recently-closed list. Rows of any other tool are never deleted (404). The loopback same-origin guard applies.
+      operationId: runHistoryForget
+      parameters:
+        - name: id
+          in: path
+          required: true
+          schema:
+            type: string
+          description: The history row's id (RunHistoryItem.id).
+          example: agenthub-lane-5-2@2026-10-06T08:00:00.000Z
+      responses:
+        '200':
+          description: Removed
+          content:
+            application/json:
+              example:
+                removed: agenthub-lane-5-2
+        '403':
+          description: 'Cross-origin rejected (EBADORIGIN). Enforced by the router-level loopback same-origin guard on every /api/run route: a browser request carrying an Origin/Referer whose host is not localhost / 127.0.0.1 / ::1 / 0.0.0.0 is refused. Requests without an Origin header (e.g. curl) are allowed.'
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/ErrorResponse'
+              example:
+                error:
+                  code: EBADORIGIN
+                  message: cross-origin requests are not allowed
+        '404':
+          description: No closed Terminal tab with that id (ENOTFOUND)
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/ErrorResponse'
+        '409':
+          description: That terminal is still open (ERUNLIVE)
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/ErrorResponse'
   /api/run/cwds:
     get:
       tags:
@@ -11594,6 +11638,44 @@ paths:
           description: '{available, branches, current, worktrees}.'
         '404':
           description: Lane not found.
+  /api/lanes/{id}/git/commit-message:
+    post:
+      tags:
+        - Lanes
+      summary: Suggest a commit message for the staged changes
+      description: Runs the user's `claude` CLI (`-p --safe-mode --no-session-persistence --tools "" --model haiku`) on the STAGED diff of the lane's cwd (or `?session=` worktree), sent on stdin with the last ten commit subjects; a `settings.local.json` is never included. Reads only — nothing is staged or committed, no tool runs and no session is saved. Same-origin, since each call spends the user's Claude quota. 400 ENOSTAGED when nothing is staged, 400 ENOTOOL when `claude` is not on PATH, 502 EAI when the CLI fails, answers empty or runs past 120 s.
+      operationId: suggestLaneCommitMessage
+      parameters:
+        - name: id
+          in: path
+          required: true
+          schema:
+            type: integer
+        - name: session
+          in: query
+          required: false
+          schema:
+            type: string
+      responses:
+        '200':
+          description: The suggested message
+          content:
+            application/json:
+              schema:
+                type: object
+                properties:
+                  message:
+                    type: string
+                required:
+                  - message
+        '400':
+          description: ENOSTAGED / ENOTOOL / ENOWORKTREE
+        '403':
+          description: Cross-origin request refused
+        '404':
+          description: No such workspace
+        '502':
+          description: EAI — the claude CLI failed
   /api/lanes/{id}/git/{action}:
     post:
       tags: