feat: enrichment Hub API, feature flags UI/gating, NCM refresher, Agent enrichment worker with tests

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

central/app/config.py

@@ -77,6 +77,11 @@ class Settings:
     # Z.ai general endpoint (NOT the /api/coding/paas/v4 coding-plan endpoint).
     ai_api_key: str = os.getenv("AI_API_KEY", "")
     ai_base_url: str = os.getenv("AI_BASE_URL", "https://api.z.ai/api/paas/v4")
+    # ---- Product enrichment (docs/product_enrichment.md): free providers only, tokens live ONLY in the Hub environment ----
+    cosmos_token: str = os.getenv("COSMOS_TOKEN", "")          # optional; without it Cosmos is NOT_CONFIGURED (not an error)
+    allow_paid_providers: bool = os.getenv("ALLOW_PAID_PROVIDERS", "0") == "1"
+    official_refresh_enabled: bool = os.getenv("OFFICIAL_REFRESH_ENABLED", "1") == "1"
+    enrichment_time_budget_seconds: float = float(os.getenv("ENRICHMENT_TIME_BUDGET_SECONDS", "4.5"))
 
 
 settings = Settings()