gizmoduck: row 264 phase A build notes, code at da9555ca2, consumer audit first pass, five proposed slices and Q1-Q7 to Sage (sage-2233, #1769, Vikunja 463)

agents/gizmoduck/work/queue-264/BUILD.md

@@ -0,0 +1,65 @@
+# Row 264 build notes (Gizmoduck)
+
+T1 item 7: independent sessions, compaction counts and clear context. Gitea #1769, Vikunja 463
+(design) and 466 (Claude compaction format, T3's dependency, linked and not built here). Brief:
+docs/plans/2026-10-21_t1-sessions.md, "T1 item 7: independent sessions, compaction counts and clear
+context" (blob ff0be0c79). Reviewer Duckworth, gate owner Sage. Branch gizmoduck/row264 from refactor
+da9555ca2. MVP due 10-27.
+
+The brief pins its code citations at cca206cdc. `git diff --stat cca206cdc da9555ca2` over every cited
+source file is empty, so F1-F11 still hold line for line. Only docs/prd/mosaic-stack.md moved.
+
+## Phase A: what the code has today
+
+- Bus. `threads` binds one `instance` per thread (schema.sql:240-250). `thread_claims` keys on
+  `thread` alone (:251-261), and `message_threads` maps a message to a thread (:262-265). Schema is
+  3j (store.mjs:17). The thread tables first appear in migrations/3d-3e.sql.
+- Launcher. `check()` refuses a second run for the same instance and thread
+  (launcher.mjs:233-240, `registry.running(b.id, instance, thread)`).
+- Seat. `threadStore()` makes one `session/` and one `claude-projects/` per thread
+  (session.mjs:51-74). The registry's running key is business, instance and thread (:215-218).
+- Runner. `stop()` sends TERM to the child group, then KILL after 5 s (runner.mjs:402-414). It has
+  no drain, no idle acknowledgement and no dequeue fence. D7 step 2 needs all three.
+
+## Consumer audit (D9), first pass
+
+`git grep -F` over packages/*/src/* and adapters/* at da9555ca2:
+
+| Name | Files and hits |
+| --- | --- |
+| `thread_claims` | broker.mjs 12, store.mjs 1 |
+| `message_threads` | broker.mjs 9 |
+| `thread_opens` | broker.mjs 4, store.mjs 1 |
+| `threadStore` | launcher.mjs 4, sandbox.mjs 7, session.mjs 3 |
+| `running(` | launcher.mjs 5, session.mjs 1 |
+
+Still to read: the broker holder, agents, end, usage, reply correlation and pending-approval paths
+named in D9, the two adapters (F5), both harness plugins, the conversation reader (F8) and the
+Console. Each gets a file:line row here before the first code commit.
+
+## Proposed slices
+
+One seat can't build D1-D9 in six days and keep every slice reviewable. I propose five candidates
+under row 264, each with its own manifest and Duckworth round:
+
+1. 264a bus. Session tables, claim key `(organization, thread, instance, session)` with a
+   generation, the D3 default session, the D9 bus mapping, `session.list|get|create|open|send` and an
+   optional session selector on the thread verbs. Tests: T1 bus half, T2 claims, T7 legacy clients and
+   the rollback refusal.
+2. 264b seat and launcher. Per-session native store and workspace, the single-writer fence, the
+   registry key with session, sandbox mounts of the selected store only, and pinned native ids in both
+   adapters. Tests: T1 run half, T2 workspace and path mutants.
+3. 264c compaction count. Host collector, exact for Pi. Claude shows `unknown` with the 466 reason
+   until that format is pinned. Tests: T3 Pi half.
+4. 264d clear. The D7 journal, the runner drain fence and idle acknowledgement, stop proof, then
+   retirement and successor in one transaction. Tests: T4, T6.
+5. 264e surface. `mosaic session` CLI and the Console chooser, count and clear confirmation. Tests:
+   T5 for the legacy single human, T7 Console half.
+
+## Phase A questions (sent to Sage)
+
+Q1-Q7 went to Sage in gizmoduck-0154. Answers land here as they come.
+
+## Runs
+
+None yet. Every run waits for Sage's CLEAR.