refactor: split oversized modules and start server src/stores layout

Consolidate format helpers under lib/format, split React Query hooks by domain, extract AuthPicker/ConfigRefHint and HTTP trigger routing, demote file-private exports, and move KV/secrets/variables/profiles/http-auths stores under src/stores with root re-exports.

Co-authored-by: Cursor <cursoragent@cursor.com>

packages/server/secrets.js

@@ -25,7 +25,7 @@ let cachedKey = null;
 /**
  * @returns {Buffer}
  */
-export function getMasterKey() {
+function getMasterKey() {
   if (cachedKey) return cachedKey;
   const raw = resolveSecretsKeyMaterial();
   cachedKey = /^[0-9a-fA-F]{64}$/.test(raw)