Harwinder Sekhon
80a2b89769
Resolves the Twelve Data API key through app_config.provider_api_key() (env → config.json → no default) instead of a hardcoded field on PlatformConfig. Adds data_provider.PROVIDER_REGISTRY + make_data_provider() so signal_aggregator and the backtester build the active provider through one seam; telegram_bot.py gets the same one-line WS-key fix now (per Task 4's already-planned edit for that line) so the suite doesn't crash on import between this commit and Task 4's full wiring pass. Claude-Session: https://claude.ai/code/session_01VPNF37MP9Kuv62B1VBrZ1b