feat: scaffold Tauri 2.0 backend foundation

Set up the Rust backend for Mission Control using Tauri 2.0:

Cargo Configuration:
- Cargo.toml: Tauri 2.0, serde, thiserror, tracing, mockall
  - Library crate (mission_control_lib) for testability
  - Binary crate for Tauri entry point
- Cargo.lock: Pinned dependencies for reproducible builds

Tauri Configuration (tauri.conf.json):
- App identifier: com.mission-control.app
- Window: 800x600, centered, hiddenTitle for clean macOS look
- Shell plugin scoped to lore, br, bv commands only
- Tray icon configured for background operation

Application Bootstrap:
- src/main.rs: Minimal entry point, delegates to lib
- src/lib.rs: Tracing setup, plugin registration, command handlers
  - Debug mode: auto-opens devtools
  - Safe window lookup (no unwrap panic)
- build.rs: Tauri build script for codegen

Architecture: The lib/bin split enables unit testing the Tauri
command handlers without launching the full app.

src-tauri/tauri.conf.json

@@ -0,0 +1,72 @@
+{
+  "$schema": "https://schema.tauri.app/config/2",
+  "productName": "Mission Control",
+  "version": "0.1.0",
+  "identifier": "com.mission-control.app",
+  "build": {
+    "beforeDevCommand": "npm run dev",
+    "devUrl": "http://localhost:1420",
+    "beforeBuildCommand": "npm run build",
+    "frontendDist": "../dist"
+  },
+  "app": {
+    "withGlobalTauri": false,
+    "windows": [
+      {
+        "title": "Mission Control",
+        "width": 800,
+        "height": 600,
+        "resizable": true,
+        "fullscreen": false,
+        "center": true,
+        "hiddenTitle": true,
+        "decorations": true,
+        "transparent": false,
+        "visible": true
+      }
+    ],
+    "trayIcon": {
+      "iconPath": "icons/icon.png",
+      "iconAsTemplate": true
+    },
+    "security": {
+      "csp": null
+    }
+  },
+  "bundle": {
+    "active": true,
+    "icon": [
+      "icons/32x32.png",
+      "icons/128x128.png",
+      "icons/128x128@2x.png",
+      "icons/icon.icns",
+      "icons/icon.ico"
+    ],
+    "targets": "all",
+    "macOS": {
+      "minimumSystemVersion": "10.15"
+    }
+  },
+  "plugins": {
+    "shell": {
+      "open": true,
+      "scope": [
+        {
+          "name": "lore",
+          "cmd": "lore",
+          "args": true
+        },
+        {
+          "name": "br",
+          "cmd": "br",
+          "args": true
+        },
+        {
+          "name": "bv",
+          "cmd": "bv",
+          "args": true
+        }
+      ]
+    }
+  }
+}