chore: initial scaffold

Vite + Vue 3 + DaisyUI SPA (project picker + Slack avatar member grid) with a
TypeScript/Node (Hono) backend proxying Napta + Slack, SQLite avatar cache via
node:sqlite, and docker-compose for Coolify deploy.

backend/src/db.ts

@@ -0,0 +1,47 @@
+import { DatabaseSync } from "node:sqlite"
+import { mkdirSync } from "node:fs"
+import { dirname } from "node:path"
+
+const dbPath = process.env.DB_PATH || "data/app.db"
+mkdirSync(dirname(dbPath), { recursive: true })
+
+export const db = new DatabaseSync(dbPath)
+
+// Cache of email -> Slack avatar URL, so we don't hit Slack on every request.
+// image_url is nullable: a NULL row means "looked up, no Slack match" (also
+// worth caching, to avoid re-querying people who aren't in Slack).
+db.exec(`
+  CREATE TABLE IF NOT EXISTS slack_avatar_cache (
+    email TEXT PRIMARY KEY,
+    image_url TEXT,
+    cached_at INTEGER NOT NULL
+  )
+`)
+
+const CACHE_TTL_MS = 7 * 24 * 60 * 60 * 1000
+
+interface CacheRow {
+  image_url: string | null
+  cached_at: number
+}
+
+// Returns the cached URL (which may be null = known-no-match), or undefined
+// when there is no fresh cache entry and the caller should query Slack.
+export function getCachedAvatar(email: string): string | null | undefined {
+  const row = db
+    .prepare("SELECT image_url, cached_at FROM slack_avatar_cache WHERE email = ?")
+    .get(email.toLowerCase()) as CacheRow | undefined
+  if (!row) return undefined
+  if (Date.now() - row.cached_at > CACHE_TTL_MS) return undefined
+  return row.image_url
+}
+
+export function setCachedAvatar(email: string, imageUrl: string | null): void {
+  db.prepare(
+    `INSERT INTO slack_avatar_cache (email, image_url, cached_at)
+     VALUES (?, ?, ?)
+     ON CONFLICT(email) DO UPDATE SET
+       image_url = excluded.image_url,
+       cached_at = excluded.cached_at`,
+  ).run(email.toLowerCase(), imageUrl, Date.now())
+}