feat(ai): implement intelligent auto-tagging system

- Added multi-provider AI infrastructure (OpenAI/Ollama)
- Implemented real-time tag suggestions with debounced analysis
- Created AI diagnostics and database maintenance tools in Settings
- Added automated garbage collection for orphan labels
- Refined UX with deterministic color hashing and interactive ghost tags

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

@@ -0,0 +1,31 @@
+import { NextRequest, NextResponse } from 'next/server';
+import { getAIProvider } from '@/lib/ai/factory';
+import { z } from 'zod';
+
+const requestSchema = z.object({
+  content: z.string().min(1, "Le contenu ne peut pas être vide"),
+});
+
+export async function POST(req: NextRequest) {
+  try {
+    const body = await req.json();
+    const { content } = requestSchema.parse(body);
+
+    const provider = getAIProvider();
+    const tags = await provider.generateTags(content);
+    console.log('[API Tags] Generated tags:', tags);
+
+    return NextResponse.json({ tags });
+  } catch (error: any) {
+    console.error('Erreur API tags:', error);
+    
+    if (error instanceof z.ZodError) {
+      return NextResponse.json({ error: error.errors }, { status: 400 });
+    }
+
+    return NextResponse.json(
+      { error: error.message || 'Erreur lors de la génération des tags' },
+      { status: 500 }
+    );
+  }
+}

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

@@ -0,0 +1,27 @@
+import { NextResponse } from 'next/server';
+import { getAIProvider } from '@/lib/ai/factory';
+
+export async function GET() {
+  try {
+    const provider = getAIProvider();
+    const providerName = process.env.AI_PROVIDER || 'openai';
+    
+    // Test simple de génération de tags sur un texte bidon
+    const testContent = "J'adore cuisiner des pâtes le dimanche soir avec ma famille.";
+    const tags = await provider.generateTags(testContent);
+    
+    return NextResponse.json({
+      status: 'success',
+      provider: providerName,
+      test_tags: tags,
+      message: 'Infrastructure IA opérationnelle'
+    });
+  } catch (error: any) {
+    console.error('Erreur test IA détaillée:', error);
+    return NextResponse.json({
+      status: 'error',
+      message: error.message,
+      stack: error.stack
+    }, { status: 500 });
+  }
+}