docs: the paused wave has landed; D-60, how much checking a merge gets; Q-9

The plan and the status documents say what is true after the merges
of 2026-10-29: served.md section 0, the 8.0.1 rows and unit Status
lines for S4.4, S5, S6, S7 and P6 (landed, with commits), the 8.0.2
resume paragraph turned into the record of what the merges found,
P6's At-merge bullet (the write-off and dedup interaction, the five
tests its interrupted gate never reached, schema 18), P9a's Done-when 1
verified by the green two-user job, D-58 and D-59 in order.

D-60 (the owner): per merge a compile and the unit's own tests; the
exhaustive gates once per batch, at the end. AGENTS.md's two gate
sentences, HANDOFF.md's merging procedure and the plan carry it, with
the reason: five full gates around five merges took twelve hours and
the one gate at the end found the same five tests.

Q-9 (open, for the owner): P6's `ledger-store` -> `ledger-import`
dependency, with the options and the recommendation; architecture.md
marks the arrow as under review. testing.md records the merge's test
changes under P6. STATUS.md gains "Now (2026-10-29)" with the gate
figures (170 suites, 2,944 tests, 77 minutes), the CI state and the
next steps; HANDOFF.md, roadmap.md, gui.md and the parties doc drop
the paused-branch wording; README counts 129 tools and about 2,950
tests.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HS8WZziDnyxunC23MUxrLp

plan/HANDOFF.md

@@ -14,18 +14,18 @@ You are the engineering manager (EM) of a team implementing the remaining work o
 4. `plan/STATUS.md` (where the live books stand) and `docs/architecture.md`.
 5. Only when a unit is assigned: that unit's section in `plan/served.md` 8.2, and the parts of 8.3 (the P4b reference design) it points into.
 
-### What is true today (2026-10-28)
+### What is true today (2026-10-29)
 
-- `main` is `44ee4083`. Landed since the hand-off: U0a, U0b, U0c, P7, P9a, P13 steps 1-3, P4b S4.1, S4.2, S4.3 (all 2026-10-26 to 2026-10-27). Live on the owner's books: P0 to P3, Projects, P4b S1 (`document_standing`); everything behind `documents_v2` waits for the owner's upgrade (Q-5).
-- Built but unmerged, on branches paused 2026-10-27: S4.4 (`002fb9f8`), S5 (`ad649be3`), S6 (`6c4480cd`), S7 (`4b4fecb9`), P6 (`ce366408`, a checkpoint whose gate never finished). Their worktrees are `../wb-<unit>`. "Resuming the paused worktrees" below is the first thing to do.
-- Not started: S4.5, P4, P5, P8, P10, P11a (starts now: D-56), P11b, P12, P13 steps 4-6.
+- `main` is `bfd453b6`. Landed since the hand-off: U0a, U0b, U0c, P7, P9a, P13 steps 1-3, P4b S4.1, S4.2, S4.3 (2026-10-26 to 2026-10-27), then S4.4, S5, S6, S7 and P6 (2026-10-29, merged from the paused branches by the planning session). Live on the owner's books: P0 to P3, Projects, P4b S1 (`document_standing`); everything behind `documents_v2` waits for the owner's upgrade (Q-5).
+- Nothing is built and unmerged. Branch `ci-fixes` (`76285434`, a fuzz target's renamed path and a regression test) is the one branch left to merge.
+- Not started: S4.5 (next), P4, P5, P8, P10, P11a (starts now: D-56; step 0 first), P11b, P12, P13 steps 4-6.
 - The plan's section 8 was rewritten on 2026-10-26 for this hand-off and revised on 2026-10-28 (section 0, "What changed on 2026-10-28"; `plan/2026-10-28_DRIFT_REPORT.md`). Sections 1 to 7 are the older design and carry strike-throughs (`~~text~~ → D-n`) and "As built" notes where the build or a decision departed; where section 8 and an earlier section disagree, section 8 is right.
 - Mutation testing is paused until unit P12 (decision D-33). Workers never run `cargo mutants`; each unit writes a "For P12" paragraph in `docs/testing.md` instead (recipe R-G).
 - The owner's live books are never touched by anyone on this team. The only books a worker uses are test fixtures and throwaway books made by `wanderbooks setup` in a scratch root. A unit's new writes are refused on the owner's books until the owner's format upgrade; merging never waits for that.
 
-### Resuming the paused worktrees (2026-10-27 pause)
+### The paused worktrees (2026-10-27 pause) landed on 2026-10-29
 
-The five branches were stopped mid-gate; nothing was merged, rebased or discarded. Resume in this order, one at a time (the single-owner rule): S4.4, S5, S6, S7, P6, then S4.5. For each: rebase on `main`; resolve the known conflicts (served.md 8.0.2, "Resuming the paused wave": `crates/ledger-cli/tests/documents.rs` is an add/add on every P4b branch after the first, concatenate; `types.rs` keeps both appends; P6 retakes schema 18 and resolves eight files); renumber the laws in `docs/verification.md` at merge (S1 is 34 on `main`; S5 35, S6 36, S7 37); re-run `just check`, and `just prove` for S7 and any branch that touched `verify/lean/` or a `Ledger` command, after the rebase, since the pause killed the running gates; review against the unit's text and its As-built block (each branch carries its own); merge; move the 8.0.1 row to landed and append to `plan/STATUS.md`. P6's checkpoint is not a reviewed unit: run its gate to the end and review its `ledger-store` → `ledger-import` dependency before merging (ask the owner if you would keep it). Q-5 and Q-8 were answered 2026-10-28 (D-57, D-58).
+Nothing is left to resume. The merges went in the 8.0.2 order with the conflicts that paragraph predicted; what P6's first complete gate found is in its As-built block (8.2) and `plan/STATUS.md`. Two lessons for the next pause: a checkpoint whose gate was interrupted is not a reviewed unit (P6's five unreached tests and the write-off interaction cost a day of gates), and in this colocated repo never run a `jj` command while a `git merge` is in progress in the same checkout (jj's auto-import resets git's index; one merge had to be redone in a scratch worktree). Q-5 and Q-8 were answered 2026-10-28 (D-57, D-58); Q-9 (P6's `ledger-store` → `ledger-import` dependency) is with the owner.
 
 ### How to run things
 
@@ -67,6 +67,7 @@ A worker's assignment is one message: the unit id, the exact section of `plan/se
 
 - Review a PR against the unit's text and `AGENTS.md`, not against taste. Check: every named test exists and passes; the recipes' files were all touched (R-C: `types.rs`, the handler, `scopes.rs`, `docs/mcp-interface.md`, the over-the-wire test; R-A: the constant, the `_is_its_own_feature` test, the `ensure_feature` call sites, the `books_p2_served_cut_over_whole` entry; R-B: `EVENT_TYPES`, the two arms, the fuzz generator, `differs_from`); the 8.0.6 checklist where the journal's shape changed; no golden figure moved unless the unit says it may; no new dependency in `ledger-core` (AGENTS.md); no path, `just` or toml word in any tool text (`tool_text_lint`).
 - Merge in the 8.0.2 order. The three single-owner moments (U0a; P4's sweep; P5's envelope) merge with no other MCP branch open. Schema numbers are taken at merge: the second unit to merge rebases and takes the next number (8.0.3).
+- **The cost of checking is proportional to the change (D-60, the owner, 2026-10-29).** Per merge: the workspace compiles (`cargo build --workspace --all-targets`) and the unit's own named tests pass; then the next merge. `just check`, `just prove` and the fuzz runs take an hour or more on this machine and run **once per batch**, after the last merge, and what they find is fixed in one pass. Push after the cheap checks; GitHub's `check` job runs `just check` on every push and is the exhaustive gate in the background. Never a full gate before and after each merge: the first wave's five branches cost twelve hours that way, and the one gate at the end found the same five tests.
 - After each merge: move the unit's row in 8.0.1 to "landed (commit, date)"; make sure its "As built" block is filled; append a paragraph to `plan/STATUS.md`.
 - Ask the owner only the questions in 10.3, at the moments stated (Q-5 when S4 lands; Q-4 before P11a's signing step; Q-6 before P9b; Q-7 when P11b starts), one at a time, in plain English, with the recommendation given there. Record the answer as a new D-n row in 10.1 and note which units it affects. Any other decision a worker needs that the plan does not make: look for it in section 10 first; if it is not there, ask the owner the same way and record it; never let a worker guess.
 - The owner's format upgrade (D-39, D-52) is the owner's own command on his books after S7 and P4 have landed (8.3.14 item 8; 5.6's P4b row). It is not a team step.