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.

CLAUDE.md

@@ -5,15 +5,13 @@ _Last synced: 58774f2 (2026-09-04) + per-node run command (`agenthub lanes node`
 ## Project mission
 - Maintain a reliable local-first dashboard for Claude Code session monitoring.
 - Preserve real-time behavior (hooks -> API -> SQLite -> WebSocket -> UI).
-- Keep MCP integration production-ready for local use (`mcp/`).
 
 ## Repo map
 - `server/`: Express API, hook ingestion, SQLite access, websocket broadcast (includes optional git upstream checks and `routes/updates.js`, plus `lib/workflow-ingest.js` which ingests on-disk Workflow-tool run journals — fleets that emit no hooks — and `lib/codex-ingest.js`, the same idea for `codex` lanes: it tails Codex's own rollout journals because Codex emits no hooks at all).
 - `client/`: React + Vite UI.
 - `scripts/`: hook installer/handler, import, seed, cleanup utilities. (Update detection lives server-side in `server/lib/update-check.js`. `POST /api/updates/apply` (only when the checkout is fast-forwardable) pulls, rebuilds, and self-restarts via `server/lib/self-restart.js` + the detached `scripts/restart-helper.js`; otherwise users run the printed manual command, surfaced in the UI and by `agenthub update-check`.)
-- `mcp/`: local MCP server exposing dashboard operations as tools. **`mcp/build/` is committed on purpose** — plugin MCP servers start before any bootstrap could build them; `scripts/check-mcp-build.js` (content hash in `mcp/build/.srchash`, run by pre-commit and `/agenthub-doctor`) keeps it honest. Rebuild with `npm run mcp:build`, never hand-edit `mcp/build/`.
-- `skills/`: this repo's skills. Because the repo root **is** the `agenthub` plugin root, this is also the plugin's skills directory — every skill here ships to anyone who installs the plugin, addressed as `/agenthub:<name>` (bare `/<name>` works as an alias). Put a skill here only if it should reach plugin users; `agenthub skills install` remains a fallback that copies `ship-feature-lane` into `~/.claude/skills/` for plain checkouts. - `agents/`: the same story for subagents — plugin root, so all five (`qc-local`, `senior-gate-reviewer`, `backend-reviewer`, `frontend-reviewer`, `mcp-reviewer`) ship as `agenthub:<name>`. This is also the source `agenthub lanes agents install` copies the two pipeline agents from into a lane's `.claude/agents/`, which is what keeps the bare `subagent_type: qc-local` working there. One file per agent, never a second copy.
-- `.claude-plugin/`: the marketplace plus the root `agenthub` plugin manifest (`"source": "./"` — the whole repo is the plugin). Its hooks are inline in `plugin.json`; its commands live in `plugins/agenthub/commands/`, which is NOT a subdirectory plugin. `scripts/plugin-bootstrap.js` runs from `SessionStart` and owns the writable runtime under `~/.claude/agent-dashboard/runtime/` — it never writes into the plugin cache, which Claude Code replaces on every update. See `docs/PLUGINS.md`.
+- `skills/`: this repo's skills. Because the repo root **is** the `agenthub` plugin root, this is also the plugin's skills directory — every skill here ships to anyone who installs the plugin, addressed as `/agenthub:<name>` (bare `/<name>` works as an alias). Put a skill here only if it should reach plugin users; `agenthub skills install` remains a fallback that copies `ship-feature-lane` into `~/.claude/skills/` for plain checkouts. - `agents/`: the same story for subagents — plugin root, so all four (`qc-local`, `senior-gate-reviewer`, `backend-reviewer`, `frontend-reviewer`) ship as `agenthub:<name>`. This is also the source `agenthub lanes agents install` copies the two pipeline agents from into a lane's `.claude/agents/`, which is what keeps the bare `subagent_type: qc-local` working there. One file per agent, never a second copy.
+- `.claude-plugin/`: the marketplace plus the root `agenthub` plugin manifest (`"source": "./"` — the whole repo is the plugin). Its hooks are inline in `plugin.json`; its commands live in `plugins/agenthub/commands/`, which is NOT a subdirectory plugin. `scripts/plugin-bootstrap.js` runs from `SessionStart` and owns the writable runtime under `~/.claude/agenthub/runtime/` — it never writes into the plugin cache, which Claude Code replaces on every update. See `docs/PLUGINS.md`.
 - **Reporting a required plugin is derived; installing one is allowlisted.** `server/lib/skill-plugins.js` reads the `/plugin:skill` strings out of the loaded pipeline templates — right for the `/agenthub-doctor` row, wrong for an install: a template is a file anyone can drop into `DASHBOARD_PIPELINES_DIR`, so installing whatever name it contains would make "edit a JSON file" mean "run this vendor's install command next session". The bootstrap installs only what `AUTO_INSTALLABLE` (a constant in that file, `superpowers` today) lists, in its DETACHED worker, never in the 10 s hook, recorded once as `state.skillPluginsSettled` (also gating `fastPathOk`), never throwing, and off under `AGENTHUB_AUTO_INSTALL_PLUGINS=0|false|off`. Do not derive an install target from a template.
 
 ## Lanes
@@ -57,15 +55,11 @@ See `docs/LANES.md` for full guide: stage reporting, custom templates, lane acti
 - Prod build/start: `npm run build` then `npm start`
 - Server tests: `npm run test:server`
 - Client tests: `npm run test:client`
-- MCP install/build/start: `npm run mcp:install`, `npm run mcp:build`, `npm run mcp:start`
-- MCP build freshness: `npm run mcp:check-build` (must pass whenever `mcp/src` changes)
-- MCP typecheck: `npm run mcp:typecheck`
 - CLI (after setup): `agenthub <command>` — terminal access to the full dashboard surface (`bin/agenthub.js`; `agenthub help` lists commands)
 
 ## Testing and verification policy
 - Backend changes: run `npm run test:server` before finishing.
 - Frontend changes: run `npm run test:client` when relevant. This includes per-screen render snapshots (`client/src/pages/__tests__/screens.snapshot.test.tsx`). If a UI change is intentional, review the snapshot diff and regenerate baselines with `cd client && npx vitest run -u`; never blindly update snapshots to make tests pass.
-- MCP changes: run `npm run mcp:typecheck` and `npm run mcp:build`.
 - If you cannot run a verification step, state exactly what was not run and why.
 
 ## Change guidelines by area