Custom RTMP saved accounts, RTMP test server, composition pipeline

- Backend: POST /providers/accounts/custom-rtmp to save reusable RTMP servers
- Backend: Encrypt rtmpUrl/streamKey in existing token fields, decrypt on GET
- Backend: Skip token revocation on DELETE for CUSTOM_RTMP accounts
- Backend: Decrypt CUSTOM_RTMP credentials into destinations on plan create/update
- Android: Add rtmpUrl/streamKey to LinkedAccount entity + shared parcelable (Room v6)
- Android: Add Custom RTMP dialog in AccountsScreen, auto-fill in plan destination picker
- Android: Handle CUSTOM_RTMP accounts in CreatePlanViewModel.loadExistingPlan
- Add local RTMP test server (tools/rtmp-server.js) with auto-ffplay on publish
- Add composition pipeline native code

package.json

@@ -0,0 +1,18 @@
+{
+  "name": "lck-control",
+  "version": "1.0.0",
+  "main": "index.js",
+  "directories": {
+    "doc": "docs"
+  },
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "description": "",
+  "dependencies": {
+    "node-media-server": "^4.2.4"
+  }
+}