feat: consume server model reasoning capabilities

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

@@ -50,6 +50,20 @@ function envelope(
 }
 
 describe('Conversation product contracts', () => {
+  it('accepts max in the persisted model and available thinking-level contract', () => {
+    const snapshot = createProductSnapshot();
+    snapshot.conversation.model = {
+      model: {
+        accountId: 'account-max',
+        modelId: 'deepseek-v4-pro',
+        thinkingLevel: 'max',
+      },
+      modelResolution: 'resolved',
+      availableThinkingLevels: ['off', 'low', 'high', 'max'],
+    };
+    expect(isConversationSnapshot(snapshot)).toBe(true);
+  });
+
   it('accepts bounded capability envelopes for every Data Service operation', () => {
     const control = new Set(['configure', 'inspect', 'list_projects', 'remove_collection', 'reset', 'remove_project']);
     const operations = [