Initial commit: Visigine (Vite client + Express/SQLite backend)

Container-ready via docker/ compose (frontend nginx + backend Node). Compose adjusted for Coolify on the prod server: frontend uses expose:80 (no host binding — host 8080 is taken by the Coolify proxy; Traefik routes visigine.de), backend ALLOWED_ORIGINS=https://visigine.de. Secrets stay in server/.env (git-ignored); see server/.env.example.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

server/lib/providers/index.js

@@ -0,0 +1,32 @@
+// Registry. If a provider's API key is missing, fall back to mock but keep
+// the original label (so the UI displays "openai (mock)" etc.).
+import * as openai from './openai.js'
+import * as perplexity from './perplexity.js'
+import * as anthropic from './anthropic.js'
+import * as mock from './mock.js'
+
+function wrapAsMock(label) {
+  return {
+    query: async (prompt, opts) => {
+      const r = await mock.query(prompt, opts)
+      return { ...r, provider: `${label} (mock)` }
+    },
+  }
+}
+
+export function getProviders() {
+  return {
+    openai:     process.env.OPENAI_KEY     ? openai     : wrapAsMock('openai'),
+    perplexity: process.env.PERPLEXITY_KEY ? perplexity : wrapAsMock('perplexity'),
+    anthropic:  process.env.ANTHROPIC_KEY  ? anthropic  : wrapAsMock('anthropic'),
+  }
+}
+
+// Returns labels for the UI: { openai: 'real' | 'mock', ... }.
+export function getProviderModes() {
+  return {
+    openai:     process.env.OPENAI_KEY     ? 'real' : 'mock',
+    perplexity: process.env.PERPLEXITY_KEY ? 'real' : 'mock',
+    anthropic:  process.env.ANTHROPIC_KEY  ? 'real' : 'mock',
+  }
+}