feat(mcp): Streamable HTTP transport + deploy; secure restoreRevision

- apps/mcp/src/http.ts: serve MCP over Streamable HTTP (MCP 2025-03-26) on
  :4021, stateless mode (sessionIdGenerator undefined), CORS on /mcp. Remote
  clients can now call the 6 tools + 4 resources without a stdio subprocess.
- deploy/mcpedia-mcp.service: supervised systemd unit (MCP_PORT=4021).
- Caddy: mcp.asepharyana.my.id -> 4021; wiki. domain now also routes /trpc/*
  to the API (was swallowed by web -> tRPC was unreachable on the domain).
- apps/api: restoreRevision tRPC mutation now requires x-webhook-secret (the
  Web UI calls @mcpedia/core directly, so this only gates the open network
  endpoint). Threads the header into tRPC Context. Secures a state-changing
  action that was anonymously callable.
Verified live: https://mcp.asepharyana.my.id/mcp initialize/tools/list/
resources/list all 200; restoreRevision no-secret -> unauthorized, with-secret
-> handler; read-only tRPC reachable via domain.

.hermes/plans/mcp-http-transport.md

@@ -0,0 +1,42 @@
+# MCP HTTP transport + deploy + review actions
+
+## Goal
+Make the MCPedia MCP server reachable over the network (not just stdio subprocess), so
+remote MCP clients (Claude, a Discord bot, a web client) can call its 6 tools + 4 resources.
+Serve via Streamable HTTP (MCP 2025-03-26 spec), deploy as a supervised systemd service,
+expose through Caddy on a dedicated subdomain.
+
+## Design decisions
+- **StreamableHTTPServerTransport, stateless mode** (`sessionIdGenerator: undefined`).
+  One McpServer + transport per request. No session map, no shared-transport connect race,
+  no memory leak. Re-registering 6 tools + 4 resources per request is negligible for a KB.
+- **New entry `apps/mcp/src/http.ts`** served by Node `http` (built-in), NOT mounted on the
+  API app — keeps the MCP app's zod-4 isolation intact (api app is zod 3).
+- **Port 4021** (next free in the 4000s range; 4020 is the API).
+- **Subdomain `mcp.asepharyana.my.id`** -> 4021 (Cloudflare `*` wildcard already proxies it;
+  Caddy auto-issues LE cert, no extra DNS work).
+- **CORS** allow on `/mcp` (remote web clients need it).
+- MCP tools are read-only (search/get/list/related + read-only resources) => open MCP is
+  low-risk. No auth on MCP itself.
+
+## Files
+- `apps/mcp/src/http.ts` (NEW) — Node http server, `/mcp` route, stateless transport.
+- `apps/mcp/package.json` — add `serve:http` script.
+- `package.json` (root) — add `mcp:http` script (absolute bun path).
+- `deploy/mcpedia-mcp.service` (NEW) — systemd unit, MCP_PORT=4021.
+- `/etc/caddy/Caddyfile` — add `mcp.asepharyana.my.id { import proxy 4021 }`.
+
+## Security finding (review, flagged not silently built)
+The tRPC `restoreRevision` mutation is exposed UNauthenticated at
+`https://wiki.asepharyana.my.id/trpc/restoreRevision` — anyone can revert a live doc.
+The web UI's restore path calls `@mcpedia/core` directly (server component), so the tRPC
+mutation is dead surface. Fix: guard the mutation with the existing WEBHOOK_SECRET header,
+or drop it from the router. Will apply the guard (consistent with /hooks auth) unless user
+prefers removal.
+
+## Verification
+- `bun --cwd apps/mcp run typecheck` green.
+- Live: `curl -XPOST https://mcp.asepharyana.my.id/mcp` initialize -> 200 + serverInfo;
+  tools/list -> 6 tools; resources/list -> 4 resources.
+- `systemctl is-active mcpedia-mcp` == active.
+- Commit + push.