feat: add Gemini ADC and access token auth (#312)

* feat: add Gemini ADC and access token auth

* feat: add Gemini token and ADC provider setup

* feat: add Gemini token and ADC provider setup

* fix: honor Gemini auth mode on restart

src/utils/providerProfile.test.ts

@@ -355,11 +355,38 @@ test('gemini profiles accept google api key fallback', () => {
   })
 
   assert.deepEqual(env, {
+    GEMINI_AUTH_MODE: 'api-key',
     GEMINI_MODEL: 'gemini-2.0-flash',
     GEMINI_API_KEY: 'gem-live',
   })
 })
 
+test('gemini profiles support access-token auth mode without persisting a key', () => {
+  const env = buildGeminiProfileEnv({
+    authMode: 'access-token',
+    model: 'gemini-2.5-flash',
+    processEnv: {},
+  })
+
+  assert.deepEqual(env, {
+    GEMINI_AUTH_MODE: 'access-token',
+    GEMINI_MODEL: 'gemini-2.5-flash',
+  })
+})
+
+test('gemini profiles support adc auth mode without persisting a key', () => {
+  const env = buildGeminiProfileEnv({
+    authMode: 'adc',
+    model: 'gemini-2.5-flash',
+    processEnv: {},
+  })
+
+  assert.deepEqual(env, {
+    GEMINI_AUTH_MODE: 'adc',
+    GEMINI_MODEL: 'gemini-2.5-flash',
+  })
+})
+
 test('gemini profiles require a key', () => {
   const env = buildGeminiProfileEnv({
     processEnv: {},
@@ -405,6 +432,39 @@ test('buildStartupEnvFromProfile applies persisted gemini settings when no provi
   assert.equal(env.GEMINI_MODEL, 'gemini-2.5-flash')
 })
 
+test('buildStartupEnvFromProfile rehydrates stored Gemini access token for access-token profile mode', async () => {
+  const env = await buildStartupEnvFromProfile({
+    persisted: profile('gemini', {
+      GEMINI_AUTH_MODE: 'access-token',
+      GEMINI_MODEL: 'gemini-2.5-flash',
+    }),
+    processEnv: {},
+    readGeminiAccessToken: () => 'token-live',
+  })
+
+  assert.equal(env.CLAUDE_CODE_USE_GEMINI, '1')
+  assert.equal(env.GEMINI_AUTH_MODE, 'access-token')
+  assert.equal(env.GEMINI_ACCESS_TOKEN, 'token-live')
+  assert.equal(env.GEMINI_API_KEY, undefined)
+  assert.equal(env.GEMINI_MODEL, 'gemini-2.5-flash')
+})
+
+test('buildStartupEnvFromProfile does not inject stored access token for adc profile mode', async () => {
+  const env = await buildStartupEnvFromProfile({
+    persisted: profile('gemini', {
+      GEMINI_AUTH_MODE: 'adc',
+      GEMINI_MODEL: 'gemini-2.5-flash',
+    }),
+    processEnv: {},
+    readGeminiAccessToken: () => 'token-live',
+  })
+
+  assert.equal(env.CLAUDE_CODE_USE_GEMINI, '1')
+  assert.equal(env.GEMINI_AUTH_MODE, 'adc')
+  assert.equal(env.GEMINI_ACCESS_TOKEN, undefined)
+  assert.equal(env.GEMINI_API_KEY, undefined)
+})
+
 test('buildStartupEnvFromProfile leaves explicit provider selections untouched', async () => {
   const processEnv = {
     CLAUDE_CODE_USE_GEMINI: '1',