fix(models): inherit baseUrl and api from provider config

When using custom providers with inline model definitions, the baseUrl
and api properties from the provider config were not being passed to
the individual models. This caused requests to be sent to the wrong
endpoint or with the wrong API format.

Changes:
- buildInlineProviderModels now copies baseUrl from provider to models
- buildInlineProviderModels now inherits api from provider if not set on model
- resolveModel fallback path now includes baseUrl from provider config

Co-Authored-By: Claude (claude-opus-4.5) <noreply@anthropic.com>

src/agents/pi-embedded-runner/model.ts

@@ -8,15 +8,25 @@ import { DEFAULT_CONTEXT_TOKENS } from "../defaults.js";
 import { normalizeModelCompat } from "../model-compat.js";
 import { normalizeProviderId } from "../model-selection.js";
 
-type InlineModelEntry = ModelDefinitionConfig & { provider: string };
+type InlineModelEntry = ModelDefinitionConfig & { provider: string; baseUrl?: string };
+type InlineProviderConfig = {
+  baseUrl?: string;
+  api?: ModelDefinitionConfig["api"];
+  models?: ModelDefinitionConfig[];
+};
 
 export function buildInlineProviderModels(
-  providers: Record<string, { models?: ModelDefinitionConfig[] }>,
+  providers: Record<string, InlineProviderConfig>,
 ): InlineModelEntry[] {
   return Object.entries(providers).flatMap(([providerId, entry]) => {
     const trimmed = providerId.trim();
     if (!trimmed) return [];
-    return (entry?.models ?? []).map((model) => ({ ...model, provider: trimmed }));
+    return (entry?.models ?? []).map((model) => ({
+      ...model,
+      provider: trimmed,
+      baseUrl: entry?.baseUrl,
+      api: model.api ?? entry?.api,
+    }));
   });
 }
 
@@ -72,6 +82,7 @@ export function resolveModel(
         name: modelId,
         api: providerCfg?.api ?? "openai-responses",
         provider,
+        baseUrl: providerCfg?.baseUrl,
         reasoning: false,
         input: ["text"],
         cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },