feat: scaffold matrix_client_pc (Wails + React-TS + mautrix-go + keyring)

Initial scaffold for issue 0147. App lives at
projects/element_agents/apps/matrix_client_pc/.

Deps:
- github.com/wailsapp/wails/v2 v2.11.0
- maunium.net/go/mautrix v0.25.2
- github.com/zalando/go-keyring v0.2.6

Next: MatrixService bindings + Login/Home React screens + helpers
(matrix_client_init, mas_oidc_loopback, keyring_token_store).

frontend/wailsjs/runtime/package.json

@@ -0,0 +1,24 @@
+{
+  "name": "@wailsapp/runtime",
+  "version": "2.0.0",
+  "description": "Wails Javascript runtime library",
+  "main": "runtime.js",
+  "types": "runtime.d.ts",
+  "scripts": {
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/wailsapp/wails.git"
+  },
+  "keywords": [
+    "Wails",
+    "Javascript",
+    "Go"
+  ],
+  "author": "Lea Anthony <lea.anthony@gmail.com>",
+  "license": "MIT",
+  "bugs": {
+    "url": "https://github.com/wailsapp/wails/issues"
+  },
+  "homepage": "https://github.com/wailsapp/wails#readme"
+}