feat(db): migrate from lowdb to SQLite with repos pattern

- Add modular DB layer (adapters, migrations, repos, helpers)
- Replace localDb/usageDb/requestDetailsDb monoliths with repos
- Add Tailscale tunnel integration & status check API
- Add /api/cli-tools/all-statuses aggregated endpoint
- Add settingsStore (Zustand) and mitm/dbReader
- Add DB unit tests (benchmark, concurrent, migration, vs-lowdb)

src/lib/db/version.js

@@ -0,0 +1,21 @@
+import fs from "node:fs";
+import path from "node:path";
+
+let cachedVersion = null;
+
+export function getAppVersion() {
+  if (cachedVersion) return cachedVersion;
+  try {
+    const pkgPath = path.join(process.cwd(), "package.json");
+    const pkg = JSON.parse(fs.readFileSync(pkgPath, "utf-8"));
+    cachedVersion = pkg.version || "0.0.0";
+  } catch {
+    cachedVersion = "0.0.0";
+  }
+  return cachedVersion;
+}
+
+export function timestampSlug(date = new Date()) {
+  const pad = (n) => String(n).padStart(2, "0");
+  return `${date.getFullYear()}${pad(date.getMonth() + 1)}${pad(date.getDate())}-${pad(date.getHours())}${pad(date.getMinutes())}${pad(date.getSeconds())}`;
+}