feat: add inherit model profile for OpenCode /model (#951)

tests/core.test.cjs

@@ -147,7 +147,7 @@ describe('resolveModelInternal', () => {
   describe('model profile structural validation', () => {
     test('all known agents resolve to a valid string for each profile', () => {
       const knownAgents = ['gsd-planner', 'gsd-executor', 'gsd-phase-researcher', 'gsd-codebase-mapper'];
-      const profiles = ['quality', 'balanced', 'budget'];
+      const profiles = ['quality', 'balanced', 'budget', 'inherit'];
       const validValues = ['inherit', 'sonnet', 'haiku', 'opus'];
 
       for (const profile of profiles) {
@@ -161,6 +161,14 @@ describe('resolveModelInternal', () => {
         }
       }
     });
+
+    test('inherit profile forces all known agents to inherit model', () => {
+      const knownAgents = ['gsd-planner', 'gsd-executor', 'gsd-phase-researcher', 'gsd-codebase-mapper'];
+      writeConfig({ model_profile: 'inherit' });
+      for (const agent of knownAgents) {
+        assert.strictEqual(resolveModelInternal(tmpDir, agent), 'inherit');
+      }
+    });
   });
 
   describe('override precedence', () => {
@@ -195,6 +203,11 @@ describe('resolveModelInternal', () => {
       assert.strictEqual(resolveModelInternal(tmpDir, 'gsd-nonexistent'), 'sonnet');
     });
 
+    test('returns sonnet for unknown agent type even with inherit profile', () => {
+      writeConfig({ model_profile: 'inherit' });
+      assert.strictEqual(resolveModelInternal(tmpDir, 'gsd-nonexistent'), 'sonnet');
+    });
+
     test('defaults to balanced profile when model_profile missing', () => {
       writeConfig({});
       // balanced profile, gsd-planner -> opus -> inherit

tests/verify-health.test.cjs

@@ -255,6 +255,34 @@ describe('validate health command', () => {
     );
   });
 
+  test('accepts inherit model_profile as valid', () => {
+    writeMinimalProjectMd(tmpDir);
+    writeMinimalRoadmap(tmpDir, ['1']);
+    writeMinimalStateMd(tmpDir);
+    fs.writeFileSync(
+      path.join(tmpDir, '.planning', 'config.json'),
+      JSON.stringify({
+        model_profile: 'inherit',
+        workflow: {
+          research: true,
+          plan_check: true,
+          verifier: true,
+          nyquist_validation: true,
+        },
+      })
+    );
+    fs.mkdirSync(path.join(tmpDir, '.planning', 'phases', '01-a'), { recursive: true });
+
+    const result = runGsdTools('validate health', tmpDir);
+    assert.ok(result.success, `Command failed: ${result.error}`);
+
+    const output = JSON.parse(result.output);
+    assert.ok(
+      !output.warnings.some(w => w.code === 'W004'),
+      `Should not warn for inherit model_profile: ${JSON.stringify(output.warnings)}`
+    );
+  });
+
   // ─── Check 6: Phase directory naming (NN-name format) ─────────────────────
 
   test('warns about incorrectly named phase directories', () => {