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

docs/IMPLEMENTATION-PLAN.md

@@ -159,14 +159,24 @@ matched its recorded SHA-256.
 **Acceptance:** another user can install from documented instructions and
 verify the deterministic behavior without credentials.
 
-### Phase 6 — Optional memory and learning features (not started)
+### Phase 6 — Optional memory and learning features (memory milestone implemented)
 
 - Design persistent memory and session-learning APIs separately.
 - Prefer V2 public APIs over assumptions about OpenCode's storage layout.
 - Add opt-in, scope controls, retention behavior, and isolation tests.
 
+**Progress:** explicit memory tools now use the V2 plugin storage API. They are
+disabled by default, session-scoped by project/session, and support separately
+opted-in canonical-project scope, explicit retrieval/deletion, and configurable
+expiry. Deterministic tests cover scope isolation and expiry. Live profile
+storage persistence and user-profile isolation, along with provider-backed
+learning proposals, remain unverified; automatic prompt/session capture is
+deliberately not implemented.
+
 **Acceptance:** explicit consent and tests prove project/session/user data
-cannot be mixed or silently uploaded.
+cannot be mixed or silently uploaded. This phase remains in progress until
+storage behavior is verified in OpenCode 2.0.24 and learning proposals receive a
+separate design and validation.
 
 ## Verification strategy