refactor: simplify getPhaseModelWithOverrides calls per code review

Address code review feedback on PR #629:
- Make settingsService parameter optional in getPhaseModelWithOverrides
- Function now handles undefined settingsService gracefully by returning defaults
- Remove redundant ternary checks in 4 call sites:
  - apps/server/src/routes/context/routes/describe-file.ts
  - apps/server/src/routes/context/routes/describe-image.ts
  - apps/server/src/routes/worktree/routes/generate-commit-message.ts
  - apps/server/src/services/auto-mode-service.ts
- Remove unused DEFAULT_PHASE_MODELS imports where applicable

apps/server/src/lib/settings-helpers.ts

@@ -15,6 +15,7 @@ import type {
   PhaseModelEntry,
   Credentials,
 } from '@automaker/types';
+import { DEFAULT_PHASE_MODELS } from '@automaker/types';
 import {
   mergeAutoModePrompts,
   mergeAgentPrompts,
@@ -502,17 +503,28 @@ export interface PhaseModelWithOverridesResult {
  * Also resolves the provider if the phase model has a providerId.
  *
  * @param phase - The phase key (e.g., 'enhancementModel', 'specGenerationModel')
- * @param settingsService - Settings service instance
+ * @param settingsService - Optional settings service instance (returns defaults if undefined)
  * @param projectPath - Optional project path for checking overrides
  * @param logPrefix - Prefix for log messages
  * @returns Promise resolving to phase model with provider info
  */
 export async function getPhaseModelWithOverrides(
   phase: PhaseModelKey,
-  settingsService: SettingsService,
+  settingsService?: SettingsService | null,
   projectPath?: string,
   logPrefix = '[SettingsHelper]'
 ): Promise<PhaseModelWithOverridesResult> {
+  // Handle undefined settingsService gracefully
+  if (!settingsService) {
+    logger.info(`${logPrefix} SettingsService not available, using default for ${phase}`);
+    return {
+      phaseModel: DEFAULT_PHASE_MODELS[phase] || { model: 'sonnet' },
+      isProjectOverride: false,
+      provider: undefined,
+      credentials: undefined,
+    };
+  }
+
   try {
     const globalSettings = await settingsService.getGlobalSettings();
     const credentials = await settingsService.getCredentials();

apps/server/src/routes/context/routes/describe-file.ts

@@ -12,7 +12,6 @@
 
 import type { Request, Response } from 'express';
 import { createLogger } from '@automaker/utils';
-import { DEFAULT_PHASE_MODELS } from '@automaker/types';
 import { PathNotAllowedError } from '@automaker/platform';
 import { resolvePhaseModel } from '@automaker/model-resolver';
 import { simpleQuery } from '../../../providers/simple-query-service.js';
@@ -161,18 +160,12 @@ ${contentToAnalyze}`;
         phaseModel: phaseModelEntry,
         provider,
         credentials,
-      } = settingsService
-        ? await getPhaseModelWithOverrides(
-            'fileDescriptionModel',
-            settingsService,
-            cwd,
-            '[DescribeFile]'
-          )
-        : {
-            phaseModel: DEFAULT_PHASE_MODELS.fileDescriptionModel,
-            provider: undefined,
-            credentials: undefined,
-          };
+      } = await getPhaseModelWithOverrides(
+        'fileDescriptionModel',
+        settingsService,
+        cwd,
+        '[DescribeFile]'
+      );
       const { model, thinkingLevel } = resolvePhaseModel(phaseModelEntry);
 
       logger.info(

apps/server/src/routes/context/routes/describe-image.ts

@@ -13,7 +13,7 @@
 
 import type { Request, Response } from 'express';
 import { createLogger, readImageAsBase64 } from '@automaker/utils';
-import { DEFAULT_PHASE_MODELS, isCursorModel } from '@automaker/types';
+import { isCursorModel } from '@automaker/types';
 import { resolvePhaseModel } from '@automaker/model-resolver';
 import { simpleQuery } from '../../../providers/simple-query-service.js';
 import * as secureFs from '../../../lib/secure-fs.js';
@@ -279,18 +279,12 @@ export function createDescribeImageHandler(
         phaseModel: phaseModelEntry,
         provider,
         credentials,
-      } = settingsService
-        ? await getPhaseModelWithOverrides(
-            'imageDescriptionModel',
-            settingsService,
-            cwd,
-            '[DescribeImage]'
-          )
-        : {
-            phaseModel: DEFAULT_PHASE_MODELS.imageDescriptionModel,
-            provider: undefined,
-            credentials: undefined,
-          };
+      } = await getPhaseModelWithOverrides(
+        'imageDescriptionModel',
+        settingsService,
+        cwd,
+        '[DescribeImage]'
+      );
       const { model, thinkingLevel } = resolvePhaseModel(phaseModelEntry);
 
       logger.info(

apps/server/src/routes/worktree/routes/generate-commit-message.ts

@@ -11,7 +11,7 @@ import { promisify } from 'util';
 import { existsSync } from 'fs';
 import { join } from 'path';
 import { createLogger } from '@automaker/utils';
-import { DEFAULT_PHASE_MODELS, isCursorModel, stripProviderPrefix } from '@automaker/types';
+import { isCursorModel, stripProviderPrefix } from '@automaker/types';
 import { resolvePhaseModel } from '@automaker/model-resolver';
 import { mergeCommitMessagePrompts } from '@automaker/prompts';
 import { ProviderFactory } from '../../../providers/provider-factory.js';
@@ -162,18 +162,12 @@ export function createGenerateCommitMessageHandler(
         phaseModel: phaseModelEntry,
         provider: claudeCompatibleProvider,
         credentials,
-      } = settingsService
-        ? await getPhaseModelWithOverrides(
-            'commitMessageModel',
-            settingsService,
-            worktreePath,
-            '[GenerateCommitMessage]'
-          )
-        : {
-            phaseModel: DEFAULT_PHASE_MODELS.commitMessageModel,
-            provider: undefined,
-            credentials: undefined,
-          };
+      } = await getPhaseModelWithOverrides(
+        'commitMessageModel',
+        settingsService,
+        worktreePath,
+        '[GenerateCommitMessage]'
+      );
       const { model } = resolvePhaseModel(phaseModelEntry);
 
       logger.info(

apps/server/src/services/auto-mode-service.ts

@@ -2318,18 +2318,12 @@ Format your response as a structured markdown document.`;
         phaseModel: phaseModelEntry,
         provider: analysisClaudeProvider,
         credentials,
-      } = this.settingsService
-        ? await getPhaseModelWithOverrides(
-            'projectAnalysisModel',
-            this.settingsService,
-            projectPath,
-            '[AutoMode]'
-          )
-        : {
-            phaseModel: DEFAULT_PHASE_MODELS.projectAnalysisModel,
-            provider: undefined,
-            credentials: undefined,
-          };
+      } = await getPhaseModelWithOverrides(
+        'projectAnalysisModel',
+        this.settingsService,
+        projectPath,
+        '[AutoMode]'
+      );
       const { model: analysisModel, thinkingLevel: analysisThinkingLevel } =
         resolvePhaseModel(phaseModelEntry);
       logger.info(