feat: major feature additions and improvements (#135)

## Summary

This PR includes major feature additions, bug fixes, comprehensive testing improvements, and responsive design enhancements!

## New Features ✨

### Plugin & MCP Management (#133, #134)
- **Plugin Management Panel**: Install, uninstall, enable/disable, and update plugins
- **MCP Server Management Panel**: Add/remove MCP servers, view detailed configuration
- **Marketplace Management**: Add/remove plugin marketplaces from GitHub
- Backend commands for full CLI integration (`list_plugins`, `install_plugin`, `add_mcp_server`, etc.)
- Beautiful UI with proper loading states, error handling, and theme support

### Visual Todo List Panel (#132)
- Real-time todo list display when Hikari uses the `TodoWrite` tool
- Shows pending/in-progress/completed status with visual indicators
- Progress bar and completion count
- Automatically clears on disconnect
- Theme-aware styling

### Clear Session History Button (#130)
- "Clear All Sessions" button in Session History panel
- Confirmation dialog with session count
- Keyboard support and accessibility features
- Gives users control over disk usage

### CLI Version Display (#131)
- Displays Claude CLI version in status bar
- Auto-polls every 30 seconds for updates
- Useful for debugging and feature compatibility

## Bug Fixes 🐛

### Stats Panel Scrolling (#136)
- **Fixed stats panel overflow**: Added scrollable container with `max-height` constraint
- Stats panel now scrolls when content (Tools Used, Historical Costs, Budget sections) gets too long
- Prevents content from overflowing off screen

### Agent Monitor Fixes (#122)
- **Fixed agents stuck in "running" state**: Added `SubagentStop` hook parsing
- **Fixed agents persisting after disconnect**: Call `clearConversation()` on disconnect
- **Fixed "Kill All" button**: Now properly marks all agents as errored
- **Fixed badge persisting after tab close**: Cleanup agents when conversation is deleted
- Comprehensive tests for agent lifecycle management

### Discord RPC Cleanup (#129)
- Removed file-based logging for Discord RPC
- Replaced with proper `tracing` framework usage
- Reduces disk usage and eliminates maintenance burden

### Close Modal Bug Fix (#128)
- Fixed close confirmation modal not triggering after Discord RPC refactor
- Removed frontend calls to deleted `log_discord_rpc` command
- Modal now works correctly after all operations

### Responsive Design Fixes (#118)
- Fixed top navigation icons getting cut off at small screen widths
- Fixed Connect button disappearing on narrow screens
- Fixed bottom status info (clock, CLI version) getting cut off
- Added flex-wrap and mobile-optimised layouts
- Icons-only mode on screens < 640px
- Vertical stacking on screens < 768px

## Testing Improvements 🧪

### Comprehensive Test Coverage (#114)
- **417 backend tests** (up from 408)
- **387 frontend tests** (up from 363)
- **61%+ backend code coverage**
- Added E2E integration tests for cross-platform notification commands
- New test files: `agents.test.ts`, comprehensive CLI parsing tests
- Tests for `debug_logger.rs`, `bridge_manager.rs`, `notifications.rs`
- Console mocking for cleaner test output
- Fixed flaky frontend tests

### Testing Documentation
- Updated CLAUDE.md with comprehensive testing guidelines
- Documented mocking approaches (console mocking, E2E command structure testing)
- Added step-by-step guide for adding tests to new features
- Goal to maintain ~100% test coverage documented

## Closes

Closes #114
Closes #118
Closes #122
Closes #128
Closes #129
Closes #130
Closes #131
Closes #132
Closes #133
Closes #134
Closes #136

## Technical Details

- All new backend commands properly registered in `lib.rs`
- CLI output parsing with comprehensive test coverage
- Cross-platform compatibility verified through E2E tests (Linux CI can test Windows commands)
- Theme-aware UI components using CSS variables throughout
- Proper TypeScript types for all new stores and components
- ESLint and Prettier compliant
- All Clippy warnings addressed

✨ This PR was created with help from Hikari~ 🌸

Reviewed-on: #135
Co-authored-by: Hikari <hikari@nhcarrigan.com>
Co-committed-by: Hikari <hikari@nhcarrigan.com>

src/lib/components/StatusBar.svelte

@@ -23,9 +23,12 @@
   import { achievementProgress } from "$lib/stores/achievements";
   import { runningAgentCount } from "$lib/stores/agents";
   import SessionHistoryPanel from "./SessionHistoryPanel.svelte";
+  import TodoPanel from "./TodoPanel.svelte";
   import GitPanel from "./GitPanel.svelte";
   import ProfilePanel from "./ProfilePanel.svelte";
   import AgentMonitorPanel from "./AgentMonitorPanel.svelte";
+  import PluginManagementPanel from "./PluginManagementPanel.svelte";
+  import McpManagementPanel from "./McpManagementPanel.svelte";
   import { conversationsStore } from "$lib/stores/conversations";
   import {
     generateContextInjection,
@@ -49,9 +52,12 @@
   let showHelp = $state(false);
   let showKeyboardShortcuts = $state(false);
   let showSessionHistory = $state(false);
+  let showTodoPanel = $state(false);
   let showGitPanel = $state(false);
   let showProfile = $state(false);
   let showAgentMonitor = $state(false);
+  let showPluginPanel = $state(false);
+  let showMcpPanel = $state(false);
   let isSummarising = $state(false);
   const progress = $derived($achievementProgress);
   const activeAgentCount = $derived($runningAgentCount);
@@ -92,6 +98,7 @@
     budget_action: "warn",
     budget_warning_threshold: 0.8,
     discord_rpc_enabled: true,
+    show_thinking_blocks: true,
   });
 
   let streamerModeActive = $state(false);
@@ -374,16 +381,16 @@
     {/if}
   </div>
 
-  <div class="flex items-center gap-3">
+  <div class="flex items-center gap-2 flex-wrap min-w-0">
     {#if streamerModeActive}
       <div
-        class="w-2.5 h-2.5 rounded-full bg-red-500 animate-pulse"
+        class="w-2.5 h-2.5 rounded-full bg-red-500 animate-pulse shrink-0"
         title="Streamer mode active (Ctrl+Shift+S to toggle)"
       ></div>
     {/if}
     <button
       onclick={() => (showProfile = true)}
-      class="p-1 text-gray-500 icon-trans-hover"
+      class="p-1 text-gray-500 icon-trans-hover shrink-0"
       title="Profile"
     >
       <svg class="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
@@ -437,6 +444,20 @@
         />
       </svg>
     </button>
+    <button
+      onclick={() => (showTodoPanel = true)}
+      class="p-1 text-gray-500 icon-trans-hover"
+      title="Todo List"
+    >
+      <svg class="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+        <path
+          stroke-linecap="round"
+          stroke-linejoin="round"
+          stroke-width="2"
+          d="M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2m-6 9l2 2 4-4"
+        />
+      </svg>
+    </button>
     <button
       onclick={() => (showGitPanel = true)}
       class="p-1 text-gray-500 icon-trans-hover"
@@ -451,6 +472,34 @@
         />
       </svg>
     </button>
+    <button
+      onclick={() => (showPluginPanel = true)}
+      class="p-1 text-gray-500 icon-trans-hover"
+      title="Plugin Management"
+    >
+      <svg class="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+        <path
+          stroke-linecap="round"
+          stroke-linejoin="round"
+          stroke-width="2"
+          d="M20 7l-8-4-8 4m16 0l-8 4m8-4v10l-8 4m0-10L4 7m8 4v10M4 7v10l8 4"
+        />
+      </svg>
+    </button>
+    <button
+      onclick={() => (showMcpPanel = true)}
+      class="p-1 text-gray-500 icon-trans-hover"
+      title="MCP Server Management"
+    >
+      <svg class="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+        <path
+          stroke-linecap="round"
+          stroke-linejoin="round"
+          stroke-width="2"
+          d="M5 12h14M5 12a2 2 0 01-2-2V6a2 2 0 012-2h14a2 2 0 012 2v4a2 2 0 01-2 2M5 12a2 2 0 00-2 2v4a2 2 0 002 2h14a2 2 0 002-2v-4a2 2 0 00-2-2m-2-4h.01M17 16h.01"
+        />
+      </svg>
+    </button>
     <button
       onclick={toggleEditor}
       disabled={connectionStatus !== "connected"}
@@ -647,7 +696,7 @@
   <!-- svelte-ignore a11y_click_events_have_key_events -->
   <!-- svelte-ignore a11y_no_static_element_interactions -->
   <div class="fixed inset-0 z-40" onclick={() => (showStats = false)}></div>
-  <div class="fixed top-14 right-4 z-50">
+  <div class="fixed top-14 right-4 z-50 max-h-[calc(100vh-4rem)] overflow-y-auto">
     <StatsDisplay
       onRequestSummary={handleCompactConversation}
       onStartFreshWithContext={handleStartFreshWithContext}
@@ -672,6 +721,10 @@
   <SessionHistoryPanel onClose={() => (showSessionHistory = false)} />
 {/if}
 
+{#if showTodoPanel}
+  <TodoPanel onClose={() => (showTodoPanel = false)} />
+{/if}
+
 {#if showGitPanel}
   <GitPanel isOpen={showGitPanel} onClose={() => (showGitPanel = false)} />
 {/if}
@@ -683,3 +736,40 @@
 {#if showAgentMonitor}
   <AgentMonitorPanel isOpen={showAgentMonitor} onClose={() => (showAgentMonitor = false)} />
 {/if}
+
+{#if showPluginPanel}
+  <PluginManagementPanel onClose={() => (showPluginPanel = false)} />
+{/if}
+
+{#if showMcpPanel}
+  <McpManagementPanel onClose={() => (showMcpPanel = false)} />
+{/if}
+
+<style>
+  /* Responsive status bar styling */
+  .status-bar {
+    display: flex;
+    flex-wrap: wrap;
+    gap: 0.5rem;
+  }
+
+  /* Make all icon buttons shrink but not grow */
+  .status-bar button {
+    flex-shrink: 0;
+  }
+
+  /* Hide version text on very small screens */
+  @media (max-width: 640px) {
+    .status-bar button span:last-of-type {
+      display: none;
+    }
+  }
+
+  /* Stack left and right sections on very small screens */
+  @media (max-width: 768px) {
+    .status-bar {
+      flex-direction: column;
+      gap: 0.75rem;
+    }
+  }
+</style>