config: drop the dead oanda.account_id (auto-execution leftover), keep it tolerated

The candle provider needs only oanda.api_token + base_url; account_id belonged to the
auto-execution daemon removed 2026-09-03 (31002cb). Removed from config.json.example and
the unused oanda_account_id() accessor deleted; the key stays in _KNOWN_OANDA so existing
config.json files keep loading. CLAUDE.md env-var list updated. Test locks all three.

Suite: 464 passed.

Claude-Session: https://claude.ai/code/session_01RWV2yLt3YXHHGVYHSQU2EE

app_config.py

@@ -89,6 +89,10 @@ _KNOWN_TOP = {"telegram", "data_providers", "scanning", "pairs", "log_level",
                "oanda", "deepseek", "agent_panel", "market_outlook",
                "violent_watch", "signal_log"}
 _KNOWN_OANDA = {
+    # "account_id" is TOLERATED but ignored: it belonged to the auto-
+    # execution daemon removed 2026-09-03 (last commit 31002cb). The candle
+    # provider needs only api_token + base_url; older config.json files
+    # still carry the key and must keep loading.
     "account_id", "api_token", "base_url",
 }
 _KNOWN_DEEPSEEK = {
@@ -458,12 +462,6 @@ def provider_api_key(
 
 # ── Oanda resolution helpers (env → config.json → default) ───────────
 
-def oanda_account_id(app: Optional[AppConfig] = None) -> str:
-    app = app or get_app_config()
-    return os.environ.get("OANDA_ACCOUNT_ID") or str(
-        app.oanda_settings.get("account_id", ""))
-
-
 def oanda_api_token(app: Optional[AppConfig] = None) -> str:
     app = app or get_app_config()
     return os.environ.get("OANDA_API_TOKEN") or str(