fix(guardian): resolve well-known provider baseUrl from pi-ai model database

When a provider (e.g. anthropic, openai) is not explicitly configured in
openclaw.json, fall back to pi-ai's built-in model database to resolve
baseUrl and api type. This avoids requiring users to manually configure
well-known providers.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

extensions/guardian/index.test.ts

@@ -463,12 +463,13 @@ describe("guardian index — resolveModelFromConfig", () => {
     expect(result.api).toBe("openai-completions"); // default
   });
 
-  it("returns partial model for known providers not in explicit config — pending SDK resolution", () => {
+  it("resolves known providers from pi-ai built-in database when not in explicit config", () => {
     const result = resolveModelFromConfig("anthropic", "claude-haiku-4-5", {});
     expect(result).toBeDefined();
     expect(result.provider).toBe("anthropic");
     expect(result.modelId).toBe("claude-haiku-4-5");
-    expect(result.baseUrl).toBeUndefined(); // will be resolved via SDK
+    expect(result.baseUrl).toBe("https://api.anthropic.com");
+    expect(result.api).toBe("anthropic-messages");
   });
 
   it("inline config provider with baseUrl is fully resolved", () => {
@@ -489,12 +490,12 @@ describe("guardian index — resolveModelFromConfig", () => {
     expect(result.apiKey).toBe("custom-key");
   });
 
-  it("preserves api type from config even without baseUrl", () => {
+  it("falls back to pi-ai database when config has empty baseUrl", () => {
     const result = resolveModelFromConfig("anthropic", "claude-haiku-4-5", {
       models: {
         providers: {
           anthropic: {
-            baseUrl: "", // empty — treated as missing
+            baseUrl: "", // empty — falls through to pi-ai
             api: "anthropic-messages",
             models: [],
           },
@@ -502,7 +503,8 @@ describe("guardian index — resolveModelFromConfig", () => {
       },
     });
 
-    expect(result.baseUrl).toBeUndefined();
+    // pi-ai resolves the baseUrl for known providers
+    expect(result.baseUrl).toBe("https://api.anthropic.com");
     expect(result.api).toBe("anthropic-messages");
   });
 });

extensions/guardian/index.ts

@@ -1,3 +1,4 @@
+import { getModels as piGetModels } from "@mariozechner/pi-ai";
 import type { OpenClawPluginApi, PluginRuntime } from "openclaw/plugin-sdk/core";
 import type { OpenClawConfig } from "openclaw/plugin-sdk/core";
 import { callGuardian } from "./guardian-client.js";
@@ -334,8 +335,25 @@ function resolveModelFromConfig(
     };
   }
 
-  // No explicit provider config — return partial model.
-  // baseUrl and api will be resolved lazily via SDK's resolveProviderInfo.
+  // No explicit provider config — try pi-ai's built-in model database.
+  // This covers well-known providers (anthropic, openai, google, etc.)
+  // that don't need explicit baseUrl config.
+  try {
+    const knownModels = piGetModels(provider as Parameters<typeof piGetModels>[0]);
+    if (knownModels.length > 0) {
+      const match = knownModels.find((m) => m.id === modelId) ?? knownModels[0];
+      return {
+        provider,
+        modelId,
+        baseUrl: match.baseUrl,
+        api: match.api,
+        headers: extractStringHeaders(providerConfig?.headers, match.headers),
+      };
+    }
+  } catch {
+    // Provider not in pi-ai's database — fall through
+  }
+
   return {
     provider,
     modelId,