docs(records): CHAT-03 seal loads no explicit extensions, lead decision 31

Co-Authored-By: Claude Opus 5.5 <[email protected]>

docs/SESSIONS.md

@@ -424,3 +424,4 @@ are never rewritten or removed; corrections are new entries.
 2026-09-27T00:28:13Z | Sage (T3 Claude Code, thread 1ef1e4f8) | goal 1, close what is open | Closed #1503, #1509 and #1511 on evidence; QUEUE rows 1, 6, 23, 24, 25 done; Gate F recorded not passed (ledger: 2 human msgs in filbert thread, pre-T3 period unmeasurable), Gate G carries it; rows 9-13 unblocked. Lead decision 29. Open: #1507, #1508.
 2026-09-27T00:31:17Z | Dewey (T3 Claude Code, thread 84fb346c) | CHAT-03 brief r3 (#1507, row 5) | BRIEF.md 2c5be6b4 (1527 lines) and REVIEW-REQUEST.md e197b882 frozen 0444 under agents/dewey/work/chat-03/; sealed engine plus overlap signals O1-O6, refuse or report unknown; C-1 withdrawn and restated for CHAT-06; Gate E map for Sage's rescope (lead decision 27); third consistency pass 17 defects fixed; sent to Filbert and Rocko as last round, pointer to Sage. No commit, no push, no source work.
 2026-09-27T00:31:38Z | Sage (T3 Claude Code, thread 1ef1e4f8) | CHAT-03 rescope | Lead decision 30 from Dewey r3 Gate E map: goal off for Console-bound seats (option a, goal to CHAT-06); cut §7 Pi dialogs, H5-H8 Pi, C-1, C-2, C-4; idle drift check to CHAT-07; C-5 to CHAT-04; reviewers told cut sections are non-blocking.
+2026-09-27T00:34:05Z | Sage (T3 Claude Code, thread 1ef1e4f8) | CHAT-03 r3 Rocko verdict | Rocko r3 (19e3fcff): one blocker, unpinned helper imports from explicit extensions. Lead decision 31: bound seats load no explicit extensions; extensions return with goal in CHAT-06 with pinned dependencies. Awaiting Filbert r3.

docs/plans/2026-09-26_lead-decisions.md

@@ -389,3 +389,17 @@ which stay with him. Each item names who decided it and what happened.
     - Filbert and Rocko review r3 only on the sections Gate E needs. A
       finding in a cut section is not blocking. After r3, Dewey removes the
       cut sections instead of rewording them.
+31. **CHAT-03 seal: no explicit extensions.** Rocko's r3 pass (report
+    19e3fcff) closed his R2 blocker and found one new one in the retained
+    seal. An explicit extension can import a helper outside its hashed
+    tree, and the helper can change after review with every hash still
+    passing. Ruling: take his first cut. A Console-bound seat loads no
+    explicit extensions. It launches with `--no-extensions` and no
+    `--extension`, and binding refuses otherwise. Goal was the only explicit
+    extension any repository seat loads (`scripts/agent-host-dev.sh` line
+    137), and decision 30 already turns it off for bound seats, so nothing
+    is lost. The seal covers only built-in code tied to the pinned Pi
+    artifact. Reviewed extensions come back with goal in CHAT-06, which
+    must pin their executable dependencies. No dependency crawler. Rocko's
+    nonblocking note goes to the build: no-turn fence cleanup must not undo
+    a concurrent force-stop, overlap or revocation fence. No round 4.