feat: add memory system activity display

Implements issue #118 to display auto-memory system operations and
provide a browser for viewing memory files.

Backend changes:
- Detect memory file operations in format_tool_description()
- Add emoji icons (📝/💾) for memory Read/Write/Edit operations
- Add list_memory_files() Tauri command to find all memory files
- Add 4 new tests for memory detection logic
- Update Tauri capabilities to allow reading .claude directory

Frontend changes:
- Create MemoryBrowserPanel component with file list and viewer
- Add memory panel to main app layout
- Support Markdown rendering of memory file contents
- Add loading states and error handling

Testing:
- All 354 Rust tests passing
- TypeScript type-checks pass

Co-Authored-By: Hikari <hikari@nhcarrigan.com>

src/routes/+page.svelte

@@ -33,6 +33,7 @@
   import AchievementsPanel from "$lib/components/AchievementsPanel.svelte";
   import UpdateNotification from "$lib/components/UpdateNotification.svelte";
   import CloseAppConfirmModal from "$lib/components/CloseAppConfirmModal.svelte";
+  import MemoryBrowserPanel from "$lib/components/MemoryBrowserPanel.svelte";
   import { debugConsoleStore } from "$lib/stores/debugConsole";
 
   let initialized = false;
@@ -513,6 +514,7 @@
     <PermissionModal />
     <UserQuestionModal />
     <ConfigSidebar />
+    <MemoryBrowserPanel />
     <AchievementNotification />
     <AchievementsPanel
       bind:isOpen={achievementPanelOpen}