chore(config): register BAMBUDDY_OIDC_* in the typo-guard

Unknown BAMBUDDY_* vars log "possible typo" on every boot, so a correct OIDC
config would have told its operator it was wrong, once per restart.

The test asserts against the reader's own variable list rather than a copied
one, so a thirteenth variable added later fails here instead of surfacing in
somebody's logs.

Refs #2593

backend/app/core/config.py

@@ -135,6 +135,20 @@ _INTENTIONAL_UNSETTINGS = {
     "LOG_DIR",  # config.py (above)
     "LOG_LEVEL",  # main.py logging setup
     "BUG_REPORT_RELAY_URL",  # config.py (above)
+    # #2593 — core/oidc_env.py reads these directly; they are not Settings
+    # fields because they map to an OIDCProvider row, not to app config.
+    "BAMBUDDY_OIDC_NAME",
+    "BAMBUDDY_OIDC_ISSUER_URL",
+    "BAMBUDDY_OIDC_CLIENT_ID",
+    "BAMBUDDY_OIDC_CLIENT_SECRET",
+    "BAMBUDDY_OIDC_SCOPES",
+    "BAMBUDDY_OIDC_ENABLED",
+    "BAMBUDDY_OIDC_AUTO_CREATE_USERS",
+    "BAMBUDDY_OIDC_AUTO_LINK_EXISTING",
+    "BAMBUDDY_OIDC_EMAIL_CLAIM",
+    "BAMBUDDY_OIDC_REQUIRE_EMAIL_VERIFIED",
+    "BAMBUDDY_OIDC_ICON_URL",
+    "BAMBUDDY_OIDC_AUTOLOGIN",
 }
 
 _known_settings_fields = {f.upper() for f in settings.model_fields}

backend/tests/unit/test_oidc_env_reader.py

@@ -116,3 +116,14 @@ def test_optional_strings_override_their_defaults(monkeypatch):
     assert cfg["scopes"] == "openid profile groups"
     assert cfg["email_claim"] == "mail"
     assert cfg["icon_url"] == "https://sso.example.com/logo.png"
+
+
+def test_every_var_the_reader_knows_is_registered_in_the_typo_guard():
+    """An unregistered BAMBUDDY_* var logs "possible typo" at every boot, which
+    would tell operators their correct config is wrong. Asserted against the
+    reader's own vars rather than a copied list, so a var added later is caught
+    here instead of in someone's logs."""
+    from backend.app.core.config import _INTENTIONAL_UNSETTINGS
+
+    unregistered = {v for v in (*REQUIRED, *OPTIONAL) if v not in _INTENTIONAL_UNSETTINGS}
+    assert not unregistered