chore: initialize monorepo with project scaffolding, configs, and CI setup

apps/coordinator-api/src/app/config.py

@@ -0,0 +1,32 @@
+from pydantic_settings import BaseSettings, SettingsConfigDict
+from typing import List, Optional
+
+
+class Settings(BaseSettings):
+    model_config = SettingsConfigDict(env_file=".env", env_file_encoding="utf-8", case_sensitive=False)
+
+    app_env: str = "dev"
+    app_host: str = "127.0.0.1"
+    app_port: int = 8011
+
+    database_url: str = "sqlite:///./coordinator.db"
+
+    client_api_keys: List[str] = ["REDACTED_CLIENT_KEY"]
+    miner_api_keys: List[str] = ["REDACTED_MINER_KEY"]
+    admin_api_keys: List[str] = ["REDACTED_ADMIN_KEY"]
+
+    hmac_secret: Optional[str] = None
+    allow_origins: List[str] = ["*"]
+
+    job_ttl_seconds: int = 900
+    heartbeat_interval_seconds: int = 10
+    heartbeat_timeout_seconds: int = 30
+
+    rate_limit_requests: int = 60
+    rate_limit_window_seconds: int = 60
+
+    receipt_signing_key_hex: Optional[str] = None
+    receipt_attestation_key_hex: Optional[str] = None
+
+
+settings = Settings()