plex: full nox module — client, tools and events (ADR 0044/0046)

Moves plex's API client and tools out of the shared hal sdk into the module,
so a Plex API change rebuilds only plex. Tools: status, search, sessions,
recently-added, refresh. And a real event design: it emits playback
started/stopped and item.added by watching the server, and consumes
module.*.download.completed to rescan so a downloader's fetch becomes a
visible item. Typechecks against the sdk; manifest parses with its emits/
consumes and broker own-secret.

Claude-Session: https://claude.ai/code/session_01LrgweAeERJYBg88c5cKDzF

modules/plex/tsconfig.json

@@ -0,0 +1,12 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "NodeNext",
+    "moduleResolution": "NodeNext",
+    "strict": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "noEmit": true
+  },
+  "include": ["client.ts", "index.ts", "tools/index.ts"]
+}