fix(pi): use Pi configured provider for Source Control AI defaults (#21693)

* fix(pi): let Source Control AI use Pi configured default

When Orca runs Pi for automatic branch names or commit messages without an explicit model override, omit --model so Pi resolves its configured provider. Preserve explicit discovered model selection and add regression coverage.

* fix(pi): preserve discovered fallback for non-Pi agents

Keep the configured-default sentinel behavior limited to agents whose default is the explicit CLI sentinel. Other dynamic agents still fall back to the first discovered model when their static default is unavailable.

* test(pi): pin configured-default dry-run arguments

Prove Source Control AI does not render the Pi configured-default sentinel as a literal model argument, and assert explicit model flag pairing positionally.

src/main/text-generation/commit-message-model-discovery-policy.ts

@@ -57,7 +57,10 @@ export function finalizeModelDiscoveryOutput(
     }
     return { success: false, error: `${spec.label} returned no available models.` }
   }
-  const defaultModelId = models.some((model) => model.id === spec.defaultModelId)
+  // A sentinel model in the static spec (for example `default`) means the CLI
+  // should keep its configured provider even when discovery lists concrete models.
+  const defaultModelId =
+    spec.defaultModelId === 'default' || models.some((model) => model.id === spec.defaultModelId)
     ? spec.defaultModelId
     : models[0].id
   return staticModelDiscoveryResult(spec, models, defaultModelId, 'probe')

src/main/text-generation/commit-message-text-generation-model-discovery.test.ts

@@ -273,8 +273,32 @@ describe('discoverCommitMessageModelsLocal', () => {
 
     await expect(pending).resolves.toMatchObject({
       success: true,
-      defaultModelId: 'github-copilot/gpt-5.4-mini',
-      models: [{ id: 'github-copilot/gpt-5.4-mini' }]
+      defaultModelId: 'default',
+      models: [{ id: 'default' }]
+    })
+  })
+
+  it('falls back to the first discovered non-Pi model when its static default is unavailable', async () => {
+    const listeners = new Map<string, (value: unknown) => void>()
+    const child = {
+      pid: 123,
+      kill: vi.fn(),
+      stdout: { on: vi.fn((event, callback) => listeners.set(`stdout:${event}`, callback)) },
+      stderr: { on: vi.fn((event, callback) => listeners.set(`stderr:${event}`, callback)) },
+      stdin: { end: vi.fn() },
+      on: vi.fn((event, callback) => listeners.set(event, callback))
+    }
+    spawnMock.mockReturnValue(child as never)
+
+    const pending = discoverCommitMessageModelsLocal('cursor', undefined)
+
+    listeners.get('stdout:data')?.(Buffer.from('gpt-5.2 - GPT-5.2\n'))
+    listeners.get('close')?.(0)
+
+    await expect(pending).resolves.toMatchObject({
+      success: true,
+      defaultModelId: 'gpt-5.2',
+      models: [{ id: 'gpt-5.2' }]
     })
   })
 
@@ -305,7 +329,7 @@ describe('discoverCommitMessageModelsLocal', () => {
 
     await expect(pending).resolves.toMatchObject({
       success: true,
-      defaultModelId: 'github-copilot/gpt-5.4-mini',
+      defaultModelId: 'default',
       models: [{ id: 'github-copilot/gpt-5.4-mini' }, { id: 'openai-codex/gpt-5.5' }]
     })
   })

src/renderer/src/lib/source-control-generation-plan.test.ts

@@ -88,6 +88,20 @@ describe('planSourceControlCommitMessageGeneration', () => {
     expect(result.ok && result.commandLabel).toBe('echo issue {linkedIssue}')
   })
 
+  it('omits Pi configured-default sentinel from dry-run command labels', () => {
+    const result = planSourceControlTextGeneration('commitMessage', {
+      agentId: 'pi',
+      model: 'default',
+      commandInputTemplate: '{basePrompt}'
+    })
+
+    expect(result.ok).toBe(true)
+    if (result.ok) {
+      expect(result.commandLabel).not.toContain('--model')
+      expect(result.commandLabel).not.toContain('default')
+    }
+  })
+
   it('shows per-action CLI arguments in dry-run command labels', () => {
     const result = planSourceControlTextGeneration('pullRequest', {
       agentId: 'codex',

src/shared/commit-message-agent-spec.test.ts

@@ -46,7 +46,7 @@ describe('COMMIT_MESSAGE_AGENT_SPECS', () => {
   it('uses the strongest available defaults for core agents', () => {
     expect(COMMIT_MESSAGE_AGENT_SPECS.claude?.defaultModelId).toBe('sonnet')
     expect(COMMIT_MESSAGE_AGENT_SPECS.codex?.defaultModelId).toBe('gpt-5.5')
-    expect(COMMIT_MESSAGE_AGENT_SPECS.pi?.defaultModelId).toBe('github-copilot/gpt-5.4-mini')
+    expect(COMMIT_MESSAGE_AGENT_SPECS.pi?.defaultModelId).toBe('default')
   })
 
   it('uses --prompt (not Claude --print) for Kimi non-interactive generation', () => {
@@ -612,3 +612,24 @@ describe('buildArgs (Antigravity)', () => {
     expect(COMMIT_MESSAGE_AGENT_SPECS.antigravity?.defaultModelId).toBe('Gemini 3.5 Flash (Medium)')
   })
 })
+
+
+describe('Pi Source Control AI model selection', () => {
+  it('leaves provider selection to Pi for the config default', () => {
+    const args = getCommitMessageAgentSpec('pi')!.buildArgs({
+      prompt: 'Name a branch',
+      model: 'default'
+    })
+    expect(args).not.toContain('--model')
+  })
+
+  it('passes an explicit discovered Pi model through', () => {
+    const args = getCommitMessageAgentSpec('pi')!.buildArgs({
+      prompt: 'Name a branch',
+      model: 'openai-codex/gpt-5.5'
+    })
+    const modelFlagIndex = args.indexOf('--model')
+    expect(modelFlagIndex).toBeGreaterThanOrEqual(0)
+    expect(args[modelFlagIndex + 1]).toBe('openai-codex/gpt-5.5')
+  })
+})

src/shared/commit-message-agent-specs-primary.ts

@@ -201,22 +201,20 @@ export function buildPrimaryCommitMessageAgentSpecs({
         '--no-context-files',
         '--mode',
         'text',
-        '--model',
-        model,
+        ...(model && model !== 'default' ? ['--model', model] : []),
         ...(thinkingLevel ? ['--thinking', thinkingLevel] : [])
       ],
       modelSource: 'dynamic',
       modelDiscovery: { binary: 'pi', args: ['--list-models'], parse: parsePiModels },
       models: [
         {
-          // Why: Pi commonly authenticates through GitHub Copilot locally; using
-          // that provider avoids selecting a raw OpenAI model when no key exists.
-          id: 'github-copilot/gpt-5.4-mini',
-          label: 'Github Copilot GPT 5.4 Mini',
-          ...withOpenAiThinking('gpt-5.4-mini')
+          // Why: the unqualified choice lets Pi use its configured provider and
+          // avoids forcing GitHub Copilot credentials during automation.
+          id: 'default',
+          label: 'Config default'
         }
       ],
-      defaultModelId: 'github-copilot/gpt-5.4-mini'
+      defaultModelId: 'default'
     }
   }
 }