feat: integrate custom features for smart context management

- Added a new integration script to manage custom features related to smart context.
- Implemented handlers for smart context operations (get, update, clear, stats) in ipc.
- Created a SmartContextStore class to manage context snippets and summaries.
- Developed hooks for React to interact with smart context (useSmartContext, useUpdateSmartContext, useClearSmartContext, useSmartContextStats).
- Included backup and restore functionality in the integration script.
- Validated integration by checking for custom modifications and file existence.

src/preload.ts

@@ -137,6 +137,11 @@ const validInvokeChannels = [
   "add-to-favorite",
   "github:clone-repo-from-url",
   "get-latest-security-review",
+  // Smart Context
+  "smart-context:get",
+  "smart-context:update",
+  "smart-context:clear",
+  "smart-context:stats",
   // Test-only channels
   // These should ALWAYS be guarded with IS_TEST_BUILD in the main process.
   // We can't detect with IS_TEST_BUILD in the preload script because