feat: Claude client + Voyage AI embed helper

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FFDuBhMKvoWjrWT3ZnGmmr

lib/claude/embed.ts

@@ -0,0 +1,14 @@
+export async function embedText(text: string): Promise<number[]> {
+  if (!process.env.VOYAGE_API_KEY) throw new Error('VOYAGE_API_KEY is not set')
+  const res = await fetch('https://api.voyageai.com/v1/embeddings', {
+    method: 'POST',
+    headers: {
+      'Content-Type': 'application/json',
+      'Authorization': `Bearer ${process.env.VOYAGE_API_KEY}`,
+    },
+    body: JSON.stringify({ input: [text], model: 'voyage-3-lite' }),
+  })
+  if (!res.ok) throw new Error(`Voyage embed failed: ${res.status}`)
+  const json = await res.json() as { data: Array<{ embedding: number[] }> }
+  return json.data[0].embedding
+}