feat: add quick actions panel for common prompts

- Add Rust backend for managing quick actions with persistent storage
- Create QuickActionsPanel component with edit/delete functionality
- Add quickActions store for frontend state management
- Move Actions and Snippets buttons to input controls row
- Include 6 default quick actions: Review PR, Run Tests, Explain File,
  Fix Error, Write Tests, and Refactor
- Support custom quick action creation and management

Closes #15

src-tauri/src/lib.rs

@@ -4,6 +4,7 @@ mod commands;
 mod config;
 mod git;
 mod notifications;
+mod quick_actions;
 mod sessions;
 mod snippets;
 mod stats;
@@ -20,6 +21,7 @@ use commands::load_saved_achievements;
 use commands::*;
 use git::*;
 use notifications::*;
+use quick_actions::*;
 use sessions::*;
 use snippets::*;
 use tauri::Manager;
@@ -120,6 +122,10 @@ pub fn run() {
             delete_snippet,
             get_snippet_categories,
             reset_default_snippets,
+            list_quick_actions,
+            save_quick_action,
+            delete_quick_action,
+            reset_default_quick_actions,
             git_status,
             git_diff,
             git_branches,