refactor: finish the AgentHub rename and drop the MCP server

Two leftovers from the rebrand, done together because they touch the same
docs and manifests.

**Data directory.** `agent-dashboard` could not simply be renamed in the
source: it names a real directory holding the live SQLite database. Startup
now moves it once, via `migrateLegacyDataDir()` in `server/lib/claude-home.js`
— a same-filesystem rename, so it is instant even at multiple gigabytes and
cannot leave two divergent copies. `getDataDir()` stays PURE and resolves to
the legacy path until the move happens; the first version of this put the
rename inside the getter, which meant `npm run test:server` relocated the
developer's real database as a side effect. The call sits behind
`require.main === module` and ahead of the router requires, because those pull
in db.js, which opens SQLite at module load. A failed rename is silent and the
old directory keeps being used: an unfashionable directory name beats a blank
database beside an unreachable one. Same treatment for the port-discovery file
(`.agent-dashboard.json` → `.agenthub.json`, old one dropped on write).

Not renamed on purpose: the Sagi localStorage keys (renaming silently resets
everyone's prefs) and the PWA manifest `id` (changing it orphans an installed
app).

**MCP server.** 4 tool calls in 46 days across 577,132 events, against 4,556
lines of TypeScript, a 2 MB committed build artifact, and a pre-commit guard
that had already blocked commits twice. Deleted: `mcp/`, the maintainer skills
and `mcp-reviewer` agent, the build check, `plugins/agenthub/.mcp.json`,
`docs/MCP.md`, 12 npm scripts, 5 Makefile targets, and every doc section
describing it.

Kept, because they are unrelated things sharing the name: the Config
Explorer's MCP tab and its API, per-lane Playwright MCP, the agenthub-config
plugin's MCP audit, and the historical `mcp__plugin_agenthub_*` events that
analytics must keep attributing.

Verified: server 1432/1432, client 459/459, tsc clean, prettier clean. Both
directions of the migration proven — a sandbox-HOME test run leaves the legacy
directory untouched, and a real boot moves it with its contents intact.

skills/update-project-docs/SKILL.md

@@ -35,7 +35,6 @@ Update docs **in the same change-set (PR/commit) as the code**, before claiming
 | **API route / response** | `docs/API.md`, `server/README.md` (routes), `ARCHITECTURE.md` (routes row), `server/openapi*.js` (code) |
 | **DB schema** | `docs/DATABASE.md`, `ARCHITECTURE.md` (ERD/schema) |
 | **WebSocket message** | `client/README.md` (Event Types), `server/README.md`,  |
-| **MCP tool** | `mcp/README.md`, `docs/MCP.md` |
 | **Feature / page / background service** | `README.md` (feature table + data-flow list), `ARCHITECTURE.md` (module table), `server/README.md` or `client/README.md` |
 | **CLI command / script** | `README.md` commands, `CLAUDE.md` / `AGENTS.md`, `INSTALL.md` / `SETUP.md` |
 | **New language** | `docs/I18N.md`, `client/src/i18n/locales/<xx>/*`, `client/src/i18n/index.ts` (add to `supportedLngs` AND the `resources` map) |
@@ -53,7 +52,7 @@ Update docs **in the same change-set (PR/commit) as the code**, before claiming
 - **Tables**: markdown tables stay pipe-balanced (header column count == every row).
 - **Mermaid**: each edited block still parses (valid `source --> target: label`).
 - **i18n**: every new English string has a `vi` entry in `client/src/i18n/locales/vi/`.
-- **Format/tests**: run `npm run format` (or `prettier --check` on touched files); for any code touched, run the verification from `CLAUDE.md` (`npm run test:server` / `test:client` / `mcp:typecheck`).
+- **Format/tests**: run `npm run format` (or `prettier --check` on touched files); for any code touched, run the verification from `CLAUDE.md` (`npm run test:server` / `test:client`).
 - State exactly which docs were updated and which were intentionally skipped (with reason), mirroring the repo's verification policy.
 
 ## Tips

skills/update-project-docs/references/doc-map.md

@@ -43,9 +43,6 @@ REST API reference (endpoints, params, example responses). Update for route/resp
 ### `docs/PLUGINS.md`
 Plugin/marketplace docs incl. an **Event Types** enumeration line — keep it in sync with the canonical event-type list.
 
-### `docs/MCP.md` + `mcp/README.md`
-MCP server + tool reference. Update for new/changed MCP tools.
-
 ### `docs/I18N.md`
 i18n architecture: **Supported languages** list, `supportedLngs`, the 15 namespaces. Update when adding a language or namespace. Client UI strings live in `client/src/i18n/locales/{en,zh,vi}/*.json` (code).
 

skills/update-project-docs/scripts/doc-coverage.sh

@@ -25,8 +25,6 @@ DOCS=(
   "docs/DATABASE.md"
   "docs/API.md"
   "docs/PLUGINS.md"
-  "docs/MCP.md"
-  "mcp/README.md"
   "docs/I18N.md"
   ".env.example"
 )