feat(cc-config): update every plugin and marketplace at once, then reload the open sessions

The plugins tab could already update one plugin or one marketplace at a time. It gains an install-wide batch and, separately, the reload step that actually makes an update take effect.

Update all runs in a DETACHED worker rather than the request handler, for a structural reason: the batch ends with the plugin the dashboard ITSELF runs from, and that step's plugin-bootstrap.js --force SIGTERMs this very server. An in-process loop would die partway through with the remaining plugins unrun and nothing left to report. Order is marketplaces (one call, no name = all) -> every other installed plugin -> AgentHub last -> one reload. Each transition is journalled to cc-update-all.json in the runtime dir, outside the plugin cache the update replaces, so whichever server is alive serves progress from it; the POST's response is only an acknowledgement.

readUpdateAll DERIVES an abandoned status for a running journal older than an hour, because a detached worker killed by a reboot leaves nobody to write the terminal entry and the button would stay wedged forever. isRunning gates a concurrent batch: two claude plugin update chains over one config dir race.

Reload is its own capability (server/lib/cc-reload.js, POST /api/cc-config/reload). /reload-plugins and /reload-skills are scoped BY CLAUDE CODE to the session that runs them, so nothing can reload a session from outside - typing into a session already running is the only real mechanism, and that is what this does, over tmux send-keys into the dashboard's live lane panes. It spawns NO claude process on purpose: a one-shot claude -p "/reload-plugins" would reload only its own short-lived session, exit, and leave a junk session in the dashboard's history - a headless run gets a full sessions row and there is no filter anywhere to suppress it. Reusing live panes means no session is created at all. Panes at a shell prompt are skipped (the text would run as a shell command) and only claude lanes are addressed, since Codex has no such command.

Update-all reloads once at the end; updating a single plugin passes reload:true and reloads immediately, and never after a failed action.

Fixes a real pre-existing bug on the way: pluginUpdate omitted -y while runClaude closes stdin, and the CLI requires it whenever stdin is not a TTY - so the per-plugin Update button failed for any plugin whose marketplace declares an install command. Also completes CcConfigChangedPayload's action union, which claimed write|delete while nine other values were already being emitted.

Verified: server 1683/1683, client 486/486 (27 new tests), build, prettier, file-header audit, openapi.yaml regenerated (117 paths). Update all was NOT executed against this machine - it would update 7 real plugins and restart the running dashboard.

server/openapi.js

@@ -2387,7 +2387,7 @@ function createOpenApiSpec() {
       "/api/updates/status": {
         get: {
           tags: ["Updates"],
-          summary: "Check whether the dashboard git checkout is behind origin",
+          summary: "Check whether a newer release of the dashboard has been published",
           operationId: "getUpdatesStatus",
           responses: {
             200: {
@@ -2398,7 +2398,7 @@ function createOpenApiSpec() {
                     type: "object",
                     additionalProperties: true,
                     description:
-                      "Includes git_repo, update_available, commits_behind, remote_ref, local_sha, remote_sha, manual_command, and optional error/message fields.",
+                      'Reads the newest published release from the forge API (derived from the origin remote) and compares its tag against this install\'s package.json version; falls back to a commit count against the canonical default branch when no release can be read, with the reason in release_check. Includes git_repo, update_available, install_kind ("plugin" | "checkout"), plugin_marketplace, local_version, shallow_clone, release_check, latest_release, latest_release_name, latest_release_url, latest_release_published_at, latest_release_notes, release_sha, commits_behind_release, commits_ahead_of_release, dev_build, commits_behind, remote_ref, local_sha, remote_sha, situation, manual_command, and optional error/message fields. dev_build is true when this install is strictly ahead of the newest release; commits_* fields are null on a shallow clone, where distances are meaningless.',
                   },
                 },
               },
@@ -2443,18 +2443,21 @@ function createOpenApiSpec() {
       "/api/updates/apply": {
         post: {
           tags: ["Updates"],
-          summary: "Pull, rebuild, and restart the dashboard when fast-forwardable",
+          summary: "Update this install to the newest release and restart the dashboard",
+          description:
+            "Two modes, chosen by how this copy was installed and never by the request body (which is ignored). checkout: fast-forward onto the release tag, npm run setup, npm run build in production, then self-restart. plugin: the install runs from ~/.claude/plugins/cache/, so a detached helper runs `claude plugin marketplace update`, `claude plugin update -y`, then plugin-bootstrap.js --force from the NEW cache directory, which stops this server and starts the new one. In both modes the response is written before anything stops the process.",
           operationId: "applyUpdate",
           responses: {
             200: {
               description:
-                "Checkout fast-forwarded and rebuilt; the process is about to self-restart",
+                'Update is being applied; the process is about to be replaced. mode: "plugin" means the detached plugin chain is running, otherwise the checkout was fast-forwarded and rebuilt in-place',
               content: {
                 "application/json": {
                   schema: {
                     type: "object",
                     additionalProperties: true,
-                    description: "Same shape as GET /api/updates/status, plus applied: true.",
+                    description:
+                      'Same shape as GET /api/updates/status, plus applied: true. In plugin mode also mode: "plugin" and runtime_dir (where the chain writes its verdict, read back afterwards as last_plugin_update).',
                   },
                 },
               },
@@ -2468,7 +2471,7 @@ function createOpenApiSpec() {
                     type: "object",
                     additionalProperties: true,
                     description:
-                      'applied: false plus reason: "up_to_date" | "not_fast_forwardable".',
+                      'applied: false plus reason: "up_to_date" | "not_fast_forwardable" | "plugin_managed". plugin_managed appears here only when a plugin-cache install has nothing newer published; when a newer release exists the plugin chain runs and the answer is 200 instead. Run /agenthub-update to force a refresh.',
                   },
                 },
               },