feat: Transform to Tauri desktop app

- Initialize Tauri v2 project with Rust backend
- Restructure project: move source files to src/ directory
- Add Tauri configuration for Windows, macOS, and Linux builds
- Update Vite config for Tauri development workflow
- Add file system and dialog permissions for native features
- Update package.json with desktop build scripts
- Update tsconfig.json paths for new src structure
- Add Tauri and desktop badges to README
- Document desktop build process and architecture

src-tauri/capabilities/default.json

@@ -0,0 +1,52 @@
+{
+  "$schema": "../gen/schemas/desktop-schema.json",
+  "identifier": "default",
+  "description": "Default capabilities for TypoGenie",
+  "windows": [
+    "main"
+  ],
+  "permissions": [
+    "core:default",
+    "dialog:default",
+    "dialog:allow-open",
+    "dialog:allow-save",
+    "fs:default",
+    "fs:allow-read-file",
+    "fs:allow-write-file",
+    "fs:allow-read-dir",
+    "fs:allow-copy-file",
+    "fs:allow-remove",
+    "fs:allow-rename",
+    "fs:allow-exists",
+    "fs:allow-mkdir",
+    {
+      "identifier": "fs:scope",
+      "allow": [
+        {
+          "path": "$HOME"
+        },
+        {
+          "path": "$HOME/**"
+        },
+        {
+          "path": "$DESKTOP"
+        },
+        {
+          "path": "$DESKTOP/**"
+        },
+        {
+          "path": "$DOCUMENT"
+        },
+        {
+          "path": "$DOCUMENT/**"
+        },
+        {
+          "path": "$DOWNLOAD"
+        },
+        {
+          "path": "$DOWNLOAD/**"
+        }
+      ]
+    }
+  ]
+}