fix: don't seed non-persistent config keys (oauth.* with flag off) (#26928)

seed_defaults inserted a row for every key in DEFAULT_CONFIG regardless
of whether the DB is authoritative for it. With ENABLE_OAUTH_PERSISTENT_CONFIG
off, the oauth.* keys were seeded from the then-current (often empty) env
values. Enabling the flag later made those stale rows override live env vars
(e.g. ENABLE_OAUTH_SIGNUP=true stopped taking effect) and further env changes
were never picked up.

Skip keys where persistent_enabled_for() is false, matching the masking the
read paths (get/get_many/get_namespace/get_all) already apply.


Claude-Session: https://claude.ai/code/session_01Vr2RCYUTXCtgtV4WMUCK86

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

backend/open_webui/models/config.py

@@ -248,6 +248,10 @@ class Config(Base):
             now = int(time.time())
             new_count = 0
             for key, value in defaults.items():
+                # Skip keys the DB is not authoritative for (e.g. oauth.* while
+                # ENABLE_OAUTH_PERSISTENT_CONFIG is off), matching the read paths.
+                if not Config.persistent_enabled_for(key):
+                    continue
                 if key not in existing_keys:
                     value = _json_value(value)
                     db.add(Config(key=key, value=value, updated_at=now))