Refactor application path handling and data storage architecture

Replace simple directory-based path system with git-aware data management that uses global data directories and proper workspace detection.

🤖 Generated with opencode
Co-Authored-By: opencode <noreply@opencode.ai>

packages/opencode/src/id/id.ts

@@ -5,6 +5,7 @@ export namespace Identifier {
   const prefixes = {
     session: "ses",
     message: "msg",
+    user: "usr",
   } as const
 
   export function schema(prefix: keyof typeof prefixes) {