Initial commit: pwweb - PipeWire WebUI

C++ backend with SSE streaming (reuses qpwgraph PipeWire callbacks).
Svelte frontend with custom SVG canvas for port-level connections.

Features:
- Live PipeWire graph via SSE
- Drag output->input port to connect
- Double-click or select+Delete to disconnect
- Node positions saved to localStorage
- Pan (drag bg) and zoom (scroll)
- Port type coloring (audio=green, midi=red, video=blue)

frontend/tsconfig.app.json

@@ -0,0 +1,21 @@
+{
+  "extends": "@tsconfig/svelte/tsconfig.json",
+  "compilerOptions": {
+    "tsBuildInfoFile": "./node_modules/.tmp/tsconfig.app.tsbuildinfo",
+    "target": "ES2023",
+    "useDefineForClassFields": true,
+    "module": "ESNext",
+    "types": ["svelte", "vite/client"],
+    "noEmit": true,
+    /**
+     * Typecheck JS in `.svelte` and `.js` files by default.
+     * Disable checkJs if you'd like to use dynamic types in JS.
+     * Note that setting allowJs false does not prevent the use
+     * of JS in `.svelte` files.
+     */
+    "allowJs": true,
+    "checkJs": true,
+    "moduleDetection": "force"
+  },
+  "include": ["src/**/*.ts", "src/**/*.js", "src/**/*.svelte"]
+}