docs: nomos agent code review — mark all fixes done except deferred C1

Every finding from the review is now implemented and verified live:
A1 (3919ec3), B1+B2 (c5ffaec), A3 (926969a), D1-D3 (76f7630), A2 (c390164),
B3 (6d4f6de), F1 (11c18e8). C1 (nomos gateway has no authentication) remains
explicitly deferred per operator instruction. Kept in plans/ (not moved to
done/) since C1 is still open, matching how other partially-complete plans
in this index are tracked.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

plans/2026-07-11-nomos-agent-code-review.md

@@ -1,6 +1,19 @@
 # 2026-07-11 — Nomos agent code review: gaps and improvement plan
 
-**Status:** Planned
+**Status:** In Progress — 2026-07-11. Every finding except C1 (A1-A3, B1-B3,
+D1-D3, E, F1) is fixed, tested, and verified live against the running stack.
+C1 (unauthenticated nomos gateway) is explicitly deferred per operator
+instruction ("leave auth out for these round of fixes") — the one item
+keeping this out of `done/`.
+
+- A1 `3919ec3`, B1+B2 `c5ffaec`, A3 `926969a`, D1-D3 `76f7630`,
+  A2 `c390164`, B3 `6d4f6de`, F1 `11c18e8`.
+- New `internal/safego` package (B1) and `cmd/nomos/store_test.go` (A2, plus
+  a regression test for the earlier plan-append fix) are the first automated
+  tests for any of this package's core logic — closing part of finding E,
+  though full coverage of agent.go/main.go remains future work.
+- C1 remains open — nomos's gateway (port 8092) still has no authentication.
+  Revisit separately.
 
 ## Scope