fix: force supportsDeveloperRole=false for non-native OpenAI endpoints (#29479)

Merged via squash.

Prepared head SHA: 1416c584ac
Co-authored-by: akramcodez <179671552+akramcodez@users.noreply.github.com>
Co-authored-by: gumadeiras <5599352+gumadeiras@users.noreply.github.com>
Reviewed-by: @gumadeiras

docs/concepts/model-providers.md

@@ -442,6 +442,9 @@ Notes:
   - `contextWindow: 200000`
   - `maxTokens: 8192`
 - Recommended: set explicit values that match your proxy/model limits.
+- For `api: "openai-completions"` on non-native endpoints (any non-empty `baseUrl` whose host is not `api.openai.com`), OpenClaw forces `compat.supportsDeveloperRole: false` to avoid provider 400 errors for unsupported `developer` roles.
+- If `baseUrl` is empty/omitted, OpenClaw keeps the default OpenAI behavior (which resolves to `api.openai.com`).
+- For safety, an explicit `compat.supportsDeveloperRole: true` is still overridden on non-native `openai-completions` endpoints.
 
 ## CLI examples
 

docs/gateway/configuration-reference.md

@@ -1961,6 +1961,7 @@ OpenClaw uses the pi-coding-agent model catalog. Add custom providers via `model
 - `models.providers.*.baseUrl`: upstream API base URL.
 - `models.providers.*.headers`: extra static headers for proxy/tenant routing.
 - `models.providers.*.models`: explicit provider model catalog entries.
+- `models.providers.*.models.*.compat.supportsDeveloperRole`: optional compatibility hint. For `api: "openai-completions"` with a non-empty non-native `baseUrl` (host not `api.openai.com`), OpenClaw forces this to `false` at runtime. Empty/omitted `baseUrl` keeps default OpenAI behavior.
 - `models.bedrockDiscovery`: Bedrock auto-discovery settings root.
 - `models.bedrockDiscovery.enabled`: turn discovery polling on/off.
 - `models.bedrockDiscovery.region`: AWS region for discovery.