feat(api): add API for one-shot prompt generatio, key authentication system and git commit message generation

Implement comprehensive API key management functionality including
generation, validation, and CRUD operations.

Changes:
- Add API key database schema and operations (create, validate, delete,
  toggle)
- Generating a commit message will now work properly with claude sdk and cursor cli and return a suggested commit message
- Implement crypto-based key generation with 'ck_' prefix
- Add session ID tracking in claude-sdk.js and cursor-cli.js
- Update database layer with API key validation and last_used tracking
- Support multi-user API key management with user association

This enables secure programmatic access to the agent service

server/database/init.sql

@@ -13,4 +13,37 @@ CREATE TABLE IF NOT EXISTS users (
 
 -- Indexes for performance
 CREATE INDEX IF NOT EXISTS idx_users_username ON users(username);
-CREATE INDEX IF NOT EXISTS idx_users_active ON users(is_active);
+CREATE INDEX IF NOT EXISTS idx_users_active ON users(is_active);
+
+-- API Keys table for external API access
+CREATE TABLE IF NOT EXISTS api_keys (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    user_id INTEGER NOT NULL,
+    key_name TEXT NOT NULL,
+    api_key TEXT UNIQUE NOT NULL,
+    created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
+    last_used DATETIME,
+    is_active BOOLEAN DEFAULT 1,
+    FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
+);
+
+CREATE INDEX IF NOT EXISTS idx_api_keys_key ON api_keys(api_key);
+CREATE INDEX IF NOT EXISTS idx_api_keys_user_id ON api_keys(user_id);
+CREATE INDEX IF NOT EXISTS idx_api_keys_active ON api_keys(is_active);
+
+-- User credentials table for storing various tokens/credentials (GitHub, GitLab, etc.)
+CREATE TABLE IF NOT EXISTS user_credentials (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    user_id INTEGER NOT NULL,
+    credential_name TEXT NOT NULL,
+    credential_type TEXT NOT NULL, -- 'github_token', 'gitlab_token', 'bitbucket_token', etc.
+    credential_value TEXT NOT NULL,
+    description TEXT,
+    created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
+    is_active BOOLEAN DEFAULT 1,
+    FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
+);
+
+CREATE INDEX IF NOT EXISTS idx_user_credentials_user_id ON user_credentials(user_id);
+CREATE INDEX IF NOT EXISTS idx_user_credentials_type ON user_credentials(credential_type);
+CREATE INDEX IF NOT EXISTS idx_user_credentials_active ON user_credentials(is_active);