docs: record Tasks 3-5 code review (APPROVE-WITH-FIXES) in plan status

Formal review on GURU-5070: cargo fmt/clippy/test green (89 tests, 0 warnings);
the 3 audit CRITICALs verified closed with no bypass; all security paths fail
closed. Non-blocking follow-ups tracked (viewer-token logout revocation, delete
dead validate_agent_key placeholder, X-Real-IP/log hygiene). Remaining for
Phase-1 exit: Task 8 e2e verification + /gc-audit security re-audit.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

specs/v2-secure-session-core/plan.md

@@ -1,5 +1,13 @@
 # v2 Secure Session Core — Implementation Plan
 
+> **STATUS 2026-05-30: Tasks 1–7 IMPLEMENTED + DEPLOYED. Tasks 3–5 now CODE-REVIEWED — verdict
+> APPROVE-WITH-FIXES (no CRITICAL/HIGH).** Compile-verified on GURU-5070: `cargo fmt --check` clean,
+> `clippy -D warnings` 0 warnings, `cargo test --workspace` 89 pass. The 3 audit CRITICALs verified
+> closed with no bypass; all security paths fail closed. Non-blocking follow-ups tracked: viewer-token
+> logout revocation (MEDIUM, TTL-bounded), delete the dead `validate_agent_key` "accept-any" placeholder
+> (MEDIUM), `X-Real-IP`/consent-comment/support-code-log hygiene (LOW). **Remaining for Phase-1 exit:
+> Task 8 (e2e verification + `/gc-audit --pass=security` re-audit).**
+>
 > Spec created: 2026-05-29
 > Status: in progress — Tasks 1-4 IMPLEMENTED 2026-05-29 (Task 4 self-reviewed, pending Code Review;
 > Tasks 1-3 code-reviewed APPROVED). Task 4 completes the KEYSTONE (secure auth/session core). Viewer-token authz