feat: CodePilot - desktop GUI for Claude Code

Full-featured desktop application built with Next.js + Electron:
- Streaming chat with Claude Code via Agent SDK
- Session management with SQLite persistence
- Project file tree and file preview
- MCP server and custom skills management
- Permission controls with Code/Plan/Ask modes
- Dark/light theme, token tracking
- macOS DMG packaging with electron-builder

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/types/index.ts

@@ -0,0 +1,364 @@
+// ==========================================
+// Database Models
+// ==========================================
+
+export interface ChatSession {
+  id: string;
+  title: string;
+  created_at: string;
+  updated_at: string;
+  model: string;
+  system_prompt: string;
+  working_directory: string;
+  sdk_session_id: string; // Claude Agent SDK session ID for resume
+  project_name: string;
+  status: 'active' | 'archived';
+  mode?: 'code' | 'plan' | 'ask';
+  needs_approval?: boolean;
+}
+
+// ==========================================
+// Project / File Types
+// ==========================================
+
+export interface ProjectInfo {
+  path: string;
+  name: string;
+  files_count: number;
+  last_modified: string;
+}
+
+export interface FileTreeNode {
+  name: string;
+  path: string;
+  type: 'file' | 'directory';
+  children?: FileTreeNode[];
+  size?: number;
+  extension?: string;
+}
+
+export interface FilePreview {
+  path: string;
+  content: string;
+  language: string;
+  line_count: number;
+}
+
+// ==========================================
+// Task Types
+// ==========================================
+
+export type TaskStatus = 'pending' | 'in_progress' | 'completed' | 'failed';
+
+export interface TaskItem {
+  id: string;
+  session_id: string;
+  title: string;
+  status: TaskStatus;
+  description: string | null;
+  created_at: string;
+  updated_at: string;
+}
+
+export interface Message {
+  id: string;
+  session_id: string;
+  role: 'user' | 'assistant';
+  content: string; // JSON string of MessageContentBlock[] for structured content
+  created_at: string;
+  token_usage: string | null; // JSON string of TokenUsage
+}
+
+// Structured message content blocks (stored as JSON in messages.content)
+export type MessageContentBlock =
+  | { type: 'text'; text: string }
+  | { type: 'tool_use'; id: string; name: string; input: unknown }
+  | { type: 'tool_result'; tool_use_id: string; content: string; is_error?: boolean }
+  | { type: 'code'; language: string; code: string };
+
+// Helper to parse message content - returns blocks or wraps plain text
+export function parseMessageContent(content: string): MessageContentBlock[] {
+  try {
+    const parsed = JSON.parse(content);
+    if (Array.isArray(parsed)) return parsed;
+  } catch {
+    // Not JSON, treat as plain text
+  }
+  return [{ type: 'text', text: content }];
+}
+
+export interface Setting {
+  id: number;
+  key: string;
+  value: string;
+}
+
+// ==========================================
+// Token Usage
+// ==========================================
+
+export interface TokenUsage {
+  input_tokens: number;
+  output_tokens: number;
+  cache_read_input_tokens?: number;
+  cache_creation_input_tokens?: number;
+  cost_usd?: number;
+}
+
+// ==========================================
+// API Request Types
+// ==========================================
+
+export interface CreateSessionRequest {
+  title?: string;
+  model?: string;
+  system_prompt?: string;
+  working_directory?: string;
+  mode?: string;
+}
+
+export interface SendMessageRequest {
+  session_id: string;
+  content: string;
+  model?: string;
+  mode?: string;
+}
+
+export interface UpdateMCPConfigRequest {
+  mcpServers: Record<string, MCPServerConfig>;
+}
+
+export interface AddMCPServerRequest {
+  name: string;
+  server: MCPServerConfig;
+}
+
+export interface UpdateSettingsRequest {
+  settings: SettingsMap;
+}
+
+// --- File API ---
+
+export interface FileTreeRequest {
+  dir: string;
+  depth?: number; // default 3
+}
+
+export interface FilePreviewRequest {
+  path: string;
+  maxLines?: number; // default 200
+}
+
+// --- Task API ---
+
+export interface CreateTaskRequest {
+  session_id: string;
+  title: string;
+  description?: string;
+}
+
+export interface UpdateTaskRequest {
+  title?: string;
+  status?: TaskStatus;
+  description?: string;
+}
+
+// --- Skill API ---
+
+export interface SkillDefinition {
+  name: string;
+  description: string;
+  prompt: string;
+  enabled: boolean;
+}
+
+export interface CreateSkillRequest {
+  name: string;
+  description: string;
+  prompt: string;
+}
+
+export interface UpdateSkillRequest {
+  description?: string;
+  prompt?: string;
+  enabled?: boolean;
+}
+
+// ==========================================
+// API Response Types
+// ==========================================
+
+export interface SessionsResponse {
+  sessions: ChatSession[];
+}
+
+export interface SessionResponse {
+  session: ChatSession;
+}
+
+export interface MessagesResponse {
+  messages: Message[];
+}
+
+export interface SuccessResponse {
+  success: true;
+}
+
+export interface ErrorResponse {
+  error: string;
+}
+
+export interface SettingsResponse {
+  settings: SettingsMap;
+}
+
+export interface PluginsResponse {
+  plugins: PluginInfo[];
+}
+
+export interface MCPConfigResponse {
+  mcpServers: Record<string, MCPServerConfig>;
+}
+
+// --- File API Responses ---
+
+export interface FileTreeResponse {
+  tree: FileTreeNode[];
+  root: string;
+}
+
+export interface FilePreviewResponse {
+  preview: FilePreview;
+}
+
+// --- Task API Responses ---
+
+export interface TasksResponse {
+  tasks: TaskItem[];
+}
+
+export interface TaskResponse {
+  task: TaskItem;
+}
+
+// --- Skill API Responses ---
+
+export interface SkillsResponse {
+  skills: SkillDefinition[];
+}
+
+export interface SkillResponse {
+  skill: SkillDefinition;
+}
+
+// ==========================================
+// SSE Event Types (streaming chat response)
+// ==========================================
+
+export type SSEEventType =
+  | 'text'               // text content delta
+  | 'tool_use'           // tool invocation info
+  | 'tool_result'        // tool execution result
+  | 'tool_output'        // streaming tool output (stderr from SDK process)
+  | 'status'             // status update (compacting, etc.)
+  | 'result'             // final result with usage stats
+  | 'error'              // error occurred
+  | 'permission_request' // permission approval needed
+  | 'done';              // stream complete
+
+export interface SSEEvent {
+  type: SSEEventType;
+  data: string;
+}
+
+// ==========================================
+// Permission Types
+// ==========================================
+
+export interface PermissionSuggestion {
+  type: string;
+  rules?: Array<{ toolName: string; ruleContent?: string }>;
+  behavior?: string;
+  destination?: string;
+}
+
+export interface PermissionRequestEvent {
+  permissionRequestId: string;
+  toolName: string;
+  toolInput: Record<string, unknown>;
+  suggestions?: PermissionSuggestion[];
+  decisionReason?: string;
+  blockedPath?: string;
+  toolUseId: string;
+  description?: string;
+}
+
+export interface PermissionResponseRequest {
+  permissionRequestId: string;
+  decision: {
+    behavior: 'allow';
+    updatedPermissions?: PermissionSuggestion[];
+  } | {
+    behavior: 'deny';
+    message?: string;
+  };
+}
+
+// ==========================================
+// Plugin / MCP Types
+// ==========================================
+
+export interface PluginInfo {
+  name: string;
+  description: string;
+  enabled: boolean;
+}
+
+export interface MCPServerConfig {
+  command: string;
+  args?: string[];
+  env?: Record<string, string>;
+  type?: 'stdio' | 'sse' | 'http';
+  url?: string;
+  headers?: Record<string, string>;
+}
+
+export interface MCPConfig {
+  mcpServers: Record<string, MCPServerConfig>;
+}
+
+// Backward-compatible alias
+export type MCPServer = MCPServerConfig;
+
+// ==========================================
+// Settings Types
+// ==========================================
+
+export interface SettingsMap {
+  [key: string]: string;
+}
+
+// Well-known setting keys
+export const SETTING_KEYS = {
+  DEFAULT_MODEL: 'default_model',
+  DEFAULT_SYSTEM_PROMPT: 'default_system_prompt',
+  THEME: 'theme',
+  PERMISSION_MODE: 'permission_mode',
+  MAX_THINKING_TOKENS: 'max_thinking_tokens',
+} as const;
+
+// ==========================================
+// Claude Client Types
+// ==========================================
+
+export interface ClaudeStreamOptions {
+  prompt: string;
+  sessionId: string;
+  sdkSessionId?: string; // SDK session ID for resuming conversations
+  model?: string;
+  systemPrompt?: string;
+  workingDirectory?: string;
+  mcpServers?: Record<string, MCPServerConfig>;
+  abortController?: AbortController;
+  permissionMode?: string;
+}