feat(plugins): add hosted web search client

tests/unit/coding-conversation-contracts.test.ts

@@ -106,6 +106,33 @@ describe('Conversation product contracts', () => {
     })).toBeNull();
   });
 
+  it('round-trips the Main-only receipt-unavailable billing state without an amount', () => {
+    const envelope = {
+      schema: 'makelore-capability.v1',
+      plugin_id: 'makelore.web-search',
+      plugin_version: '1.0.0',
+      capability_id: 'web-search.search',
+      operation: 'search',
+      request_id: 'pi:run-a:resource-a',
+      success: false,
+      status: 503,
+      code: 'plugin_receipt_unavailable',
+      error: 'Web Search billing status could not be synchronized; do not retry automatically',
+      retryable: false,
+      billing: { mode: 'platform_metered', status: 'receipt_unavailable' },
+      payload_schema: 'web-search.v1',
+      data: null,
+    };
+    expect(productToolDetails(envelope)).toMatchObject({
+      plugin_id: 'makelore.web-search',
+      billing: { mode: 'platform_metered', status: 'receipt_unavailable' },
+      data: null,
+    });
+    expect(productToolDetails({ ...envelope, billing: {
+      mode: 'platform_metered', status: 'receipt_unavailable', reserved_points: '0.00',
+    } })).toBeNull();
+  });
+
   it('accepts schema v1 snapshots and fail-closes unknown schemas until replacement', () => {
     const snapshot = createProductSnapshot();
     expect(isConversationSnapshot(snapshot)).toBe(true);