feat: AI provider testing page + multi-provider support + UX design spec

- Add AI Provider Testing page (/admin/ai-test) with Tags and Embeddings tests
- Add new AI providers: CustomOpenAI, DeepSeek, OpenRouter
- Add API routes for AI config, models listing, and testing endpoints
- Add UX Design Specification document for Phase 1 MVP AI
- Add PRD Phase 1 MVP AI planning document
- Update admin settings and sidebar navigation
- Fix AI factory for multi-provider support

keep-notes/app/api/ai/test/route.ts

@@ -1,55 +1,88 @@
 import { NextRequest, NextResponse } from 'next/server'
-import { getAIProvider } from '@/lib/ai/factory'
+import { getTagsProvider, getEmbeddingsProvider } from '@/lib/ai/factory'
 import { getSystemConfig } from '@/lib/config'
 
+function getProviderDetails(config: Record<string, string>, providerType: string) {
+  const provider = providerType.toLowerCase()
+
+  switch (provider) {
+    case 'ollama':
+      return {
+        provider: 'Ollama',
+        baseUrl: config.OLLAMA_BASE_URL || process.env.OLLAMA_BASE_URL || 'http://localhost:11434',
+        model: config.AI_MODEL_EMBEDDING || 'embeddinggemma:latest'
+      }
+    case 'openai':
+      return {
+        provider: 'OpenAI',
+        baseUrl: 'https://api.openai.com/v1',
+        model: config.AI_MODEL_EMBEDDING || 'text-embedding-3-small'
+      }
+    case 'custom':
+      return {
+        provider: 'Custom OpenAI',
+        baseUrl: config.CUSTOM_OPENAI_BASE_URL || process.env.CUSTOM_OPENAI_BASE_URL || 'Not configured',
+        model: config.AI_MODEL_EMBEDDING || 'text-embedding-3-small'
+      }
+    default:
+      return {
+        provider: provider,
+        baseUrl: 'unknown',
+        model: config.AI_MODEL_EMBEDDING || 'unknown'
+      }
+  }
+}
+
 export async function GET(request: NextRequest) {
   try {
     const config = await getSystemConfig()
-    const provider = getAIProvider(config)
+    const tagsProvider = getTagsProvider(config)
+    const embeddingsProvider = getEmbeddingsProvider(config)
 
-    // Test with a simple embedding request
     const testText = 'test'
-    const embeddings = await provider.getEmbeddings(testText)
+
+    // Test embeddings provider
+    const embeddings = await embeddingsProvider.getEmbeddings(testText)
 
     if (!embeddings || embeddings.length === 0) {
+      const providerType = config.AI_PROVIDER_EMBEDDING || 'ollama'
+      const details = getProviderDetails(config, providerType)
       return NextResponse.json(
         {
           success: false,
-          provider: config.AI_PROVIDER || 'ollama',
+          tagsProvider: config.AI_PROVIDER_TAGS || 'ollama',
+          embeddingsProvider: providerType,
           error: 'No embeddings returned',
-          details: {
-            provider: config.AI_PROVIDER || 'ollama',
-            baseUrl: config.OLLAMA_BASE_URL || process.env.OLLAMA_BASE_URL || 'http://localhost:11434',
-            model: config.AI_MODEL_EMBEDDING || process.env.OLLAMA_EMBEDDING_MODEL || 'embeddinggemma:latest'
-          }
+          details
         },
         { status: 500 }
       )
     }
 
+    const tagsProviderType = config.AI_PROVIDER_TAGS || 'ollama'
+    const embeddingsProviderType = config.AI_PROVIDER_EMBEDDING || 'ollama'
+    const details = getProviderDetails(config, embeddingsProviderType)
+
     return NextResponse.json({
       success: true,
-      provider: config.AI_PROVIDER || 'ollama',
+      tagsProvider: tagsProviderType,
+      embeddingsProvider: embeddingsProviderType,
       embeddingLength: embeddings.length,
       firstValues: embeddings.slice(0, 5),
-      details: {
-        provider: config.AI_PROVIDER || 'ollama',
-        baseUrl: config.OLLAMA_BASE_URL || process.env.OLLAMA_BASE_URL || 'http://localhost:11434',
-        model: config.AI_MODEL_EMBEDDING || process.env.OLLAMA_EMBEDDING_MODEL || 'embeddinggemma:latest'
-      }
+      details
     })
   } catch (error: any) {
     console.error('AI test error:', error)
+    const config = await getSystemConfig()
+    const providerType = config.AI_PROVIDER_EMBEDDING || 'ollama'
+    const details = getProviderDetails(config, providerType)
+
     return NextResponse.json(
       {
         success: false,
         error: error.message || 'Unknown error',
         stack: process.env.NODE_ENV === 'development' ? error.stack : undefined,
-        details: {
-          provider: process.env.AI_PROVIDER || 'ollama',
-          baseUrl: process.env.OLLAMA_BASE_URL || 'http://localhost:11434',
-          model: process.env.OLLAMA_EMBEDDING_MODEL || 'embeddinggemma:latest'
-        }
+        details
       },
       { status: 500 }
     )