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/perplexity.js

@@ -0,0 +1,64 @@
+// Perplexity is the highest-priority provider — it is an actual AI search
+// engine, where real users go for recommendations. OpenAI-compatible schema.
+const ENDPOINT = 'https://api.perplexity.ai/chat/completions'
+const MODEL = 'sonar'
+const TIMEOUT_MS = 30_000
+const SYSTEM_PROMPT =
+  'You are a helpful AI search assistant. Answer the user\'s question concisely, in German if the question is in German. Recommend specific companies, services, or products when relevant.'
+
+// Approximate per-1M token rates in USD for `sonar`.
+const COST = { inputPer1M: 1.00, outputPer1M: 1.00 }
+
+async function once(prompt, signal) {
+  return fetch(ENDPOINT, {
+    method: 'POST',
+    signal,
+    headers: {
+      'Content-Type': 'application/json',
+      Authorization: `Bearer ${process.env.PERPLEXITY_KEY}`,
+    },
+    body: JSON.stringify({
+      model: MODEL,
+      temperature: 0.3,
+      max_tokens: 600,
+      messages: [
+        { role: 'system', content: SYSTEM_PROMPT },
+        { role: 'user', content: prompt },
+      ],
+    }),
+  })
+}
+
+export async function query(prompt) {
+  const t0 = Date.now()
+  const controller = new AbortController()
+  const timer = setTimeout(() => controller.abort(), TIMEOUT_MS)
+  try {
+    let res = await once(prompt, controller.signal)
+    if (res.status >= 500) {
+      res = await once(prompt, controller.signal)
+    }
+    if (!res.ok) {
+      return { provider: 'perplexity', content: '', ms: Date.now() - t0, costUsd: 0, error: `PERPLEXITY_${res.status}` }
+    }
+    const data = await res.json()
+    const content = data?.choices?.[0]?.message?.content || ''
+    const inTok = data?.usage?.prompt_tokens || 0
+    const outTok = data?.usage?.completion_tokens || 0
+    // Fall back to a character-based rough estimate if usage is absent.
+    let costUsd
+    if (inTok || outTok) {
+      costUsd = (inTok * COST.inputPer1M + outTok * COST.outputPer1M) / 1_000_000
+    } else {
+      const approxIn = Math.ceil((prompt.length + SYSTEM_PROMPT.length) / 4)
+      const approxOut = Math.ceil(content.length / 4)
+      costUsd = (approxIn * COST.inputPer1M + approxOut * COST.outputPer1M) / 1_000_000
+    }
+    return { provider: 'perplexity', content, ms: Date.now() - t0, costUsd, error: null }
+  } catch (e) {
+    const code = e?.name === 'AbortError' ? 'TIMEOUT' : 'NETWORK'
+    return { provider: 'perplexity', content: '', ms: Date.now() - t0, costUsd: 0, error: code }
+  } finally {
+    clearTimeout(timer)
+  }
+}