feat(memory): add opt-in scoped memory tools

TODO.md

@@ -34,6 +34,10 @@
 
 ## Follow-up
 
+- [ ] Verify plugin-storage persistence and session/project isolation in a live
+  OpenCode 2.0.24 profile; design opt-in learning proposals as a separate step.
+- [ ] Decide whether memory needs a bulk-clear command and background expiry
+  cleanup before adding automatic learning.
 - [ ] Add a diagnostic command for installation state and supported versions.
 - [ ] Evaluate global/XDG installation only if project-local usage proves
   insufficient.