feat: start-at-login is a Settings switch, off by default (v2.5.0)

- Settings → About → "Start AgentHub automatically" (AutostartSettings.tsx,
  GET/PUT /api/settings/autostart, server/lib/autostart.js). The switch is
  the systemd --user unit's / LaunchAgent's enabled state: on writes a unit
  for the running server when none exists and enables it, off disables it;
  neither starts or stops the server. A foreign unit is never touched
  (409 EFOREIGN)
- The plugin bootstrap no longer installs a unit on every install: it
  installs or starts one only while the user has it enabled, and a rewrite
  keeps the enabled state (writeUserService({ enable })). An install that
  already had the unit enabled stays on. A stale-but-enabled unit beside a
  live detached server is repointed, no longer started onto the bound port
- unitIsEnabled / setUnitEnabled in systemd-service.js and launchd-service.js

Also:
- fix(workspace): status bar no longer covers the chat box below md (#61)

openapi.yaml

@@ -3,7 +3,7 @@
 openapi: 3.0.3
 info:
   title: Agent Dashboard for Claude Code API
-  version: 2.4.0
+  version: 2.5.0
   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
@@ -12585,6 +12585,88 @@ paths:
                 results:
                   - id: src_a
                     ok: true
+  /api/settings/autostart:
+    get:
+      tags:
+        - Settings
+      summary: Whether the dashboard starts at boot/login
+      description: The per-user service's enabled state (a systemd `--user` unit, or a LaunchAgent on macOS). Off by default.
+      operationId: getAutostart
+      responses:
+        '200':
+          description: Start-at-login state
+          content:
+            application/json:
+              schema:
+                type: object
+                required:
+                  - available
+                  - kind
+                  - enabled
+                  - foreign
+                properties:
+                  available:
+                    type: boolean
+                    description: False with no systemd --user (Linux) or GUI login (macOS)
+                  kind:
+                    type: string
+                    enum:
+                      - systemd
+                      - launchd
+                  enabled:
+                    type: boolean
+                  foreign:
+                    type: boolean
+                    description: A unit named agenthub exists that AgentHub did not write
+    put:
+      tags:
+        - Settings
+      summary: Turn start-at-login on or off
+      description: Enables or disables the unit, writing one for the running server first when none exists. Never starts or stops the server. Same-origin only.
+      operationId: setAutostart
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              type: object
+              required:
+                - enabled
+              properties:
+                enabled:
+                  type: boolean
+      responses:
+        '200':
+          description: The new state
+          content:
+            application/json:
+              schema:
+                type: object
+                required:
+                  - available
+                  - kind
+                  - enabled
+                  - foreign
+                properties:
+                  available:
+                    type: boolean
+                    description: False with no systemd --user (Linux) or GUI login (macOS)
+                  kind:
+                    type: string
+                    enum:
+                      - systemd
+                      - launchd
+                  enabled:
+                    type: boolean
+                  foreign:
+                    type: boolean
+                    description: A unit named agenthub exists that AgentHub did not write
+        '400':
+          description: 'EBADVALUE: `enabled` is not a boolean; EUNAVAILABLE: no systemd --user / launchd GUI session'
+        '403':
+          description: 'EBADORIGIN: another site asked'
+        '409':
+          description: 'EFOREIGN: a unit named agenthub that AgentHub did not write'
   /api/settings/codex-hooks:
     get:
       tags: