docs: the parked claim and the one-build-at-a-time rule

The one-issue-at-a-time bullet counted claims when it meant build work
in flight; the 2026-07-23 board (#15, #16 parked beside #73) proved the
count wrong. BUILDER.md now defines the three parked shapes, the
declared-never-inferred park comment, and unparking; TRIAGE.md names a
directed hold as a park (#77).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

BUILDER.md

@@ -11,8 +11,30 @@ triage bug, and the move is to say so on the issue, not to guess.
 - Respect dependency order: inside an epic, take the earliest unblocked
   unclaimed child. Between epics and strays, prefer the issue that unblocks
   the most other work.
-- **One issue at a time.** Finish or release your claim before taking
+- **One build at a time.** You hold at most one issue on which you are
-  another.
+  writing or revising a deliverable — finish or release that work before
+  starting new work. The rule counts build work in flight, not claims: a
+  claim does not consume the slot while it is **parked**, meaning the next
+  move belongs to someone else. Exactly three shapes qualify:
+  1. the issue carries `needs-ruling`, its escalation names a decider, and
+     its `Blocked:` line stops the remaining work;
+  2. the deliverable is in a review round where every outstanding verdict
+     belongs to someone else — the round was answered whole and the
+     non-approvers re-requested (the review round, step 2);
+  3. every remaining acceptance criterion is operator-owned, stated as such
+     by triage on the issue.
+  Not parked — these are what the rule defends against: waiting on
+  yourself, waiting on CI, or waiting for a good moment. An issue you have
+  simply stopped working on is not parked either — that is abandonment,
+  and its move is unchanged: unassign and restore `ready` (Claiming,
+  below).
+  The 2026-07-23 board is why the rule counts work and not claims: one
+  builder correctly held
+  [#15](https://github.com/heavy-duty/ceremony/issues/15) (`offsite`,
+  round answered whole, one verdict outstanding) and
+  [#16](https://github.com/heavy-duty/ceremony/issues/16) (`needs-ruling`
+  hard block, triage said hold) parked beside the one active build,
+  [#73](https://github.com/heavy-duty/ceremony/issues/73).
 
 ## Claiming
 
@@ -20,6 +42,21 @@ triage bug, and the move is to say so on the issue, not to guess.
   starting. The claim is a promise of a draft PR soon — a claim with no PR
   and no activity is what the staleness sweep reclaims unless `offsite`
   records that its PR lives in another repository.
+- **A park is declared, never inferred.** When your claim enters a parked
+  shape (Picking, above), say so in a comment on that issue, naming what it
+  waits on and who owns the next move. No new label: the comment is
+  activity, so it feeds the same reclaim clock the `needs-ruling`
+  ([#52](https://github.com/heavy-duty/ceremony/issues/52)) and `offsite`
+  ([#68](https://github.com/heavy-duty/ceremony/issues/68)) exemptions
+  already guard — a parked claim nobody can name is an abandoned one.
+- **Unparking is a claim like any other.** When the wait ends, the parked
+  issue is work again and takes the slot. If you are already active
+  elsewhere, finish or release that work first, and say which you did on
+  both issues — the slot is still one. Nothing counts claims per builder
+  and no reconciler path enforces any of this: `claim_decision()` sees one
+  issue at a time by construction, and no such machinery should be built
+  expecting it to have been specified here. The discipline is the
+  declaration, not a counter.
 - **Abandoning is fine; ghosting is not.** If you stop, say where you got to,
   push the branch if it holds anything useful, unassign, and restore
   `ready`.

CHANGELOG.md

@@ -16,6 +16,7 @@ so entries say what changed, cite the issue, and stop.
 - Ruling doctrine — define every human-owned trigger, the fixed escalation shape, and the 0–24h builder-to-triage ladder (#72).
 - The sweep observes the escalation contract: a malformed escalation is named field-by-field, and the ladder's 12h/24h rungs each draw one comment to the flag-setter — comment-only, per-episode, both surfaces (#73).
 - FLEET.md — the operator notifier's `needs-ruling` queue (one tracked message per item, edited in place across the rungs) and triage's past-24h wake condition; a spec on paper until an operator updates the box (#74).
+- One issue at a time counts build work in flight: the parked claim's three shapes, its declared-never-inferred comment, and triage's duty to name a directed hold as a park (#77).
 
 ## 0.1.0 — 2026-07-22
 

TRIAGE.md

@@ -44,6 +44,10 @@ is the failure this whole flow exists to prevent.
    blocks something already on the board — an existing issue, or minted work
    a discussion's ruling gates — set `needs-ruling` on it too, so the board
    shows where the human's turn is; the issue keeps its queue label.
+   When you direct a builder to hold a claim that has no build work left,
+   say the claim is **parked** and name what it waits on — the directive
+   and the builder's doctrine
+   ([BUILDER.md](BUILDER.md#claiming)) must use one word.
    Past 24 hours from the current episode's `labeled` event, if the ruling
    still stands and doubt remains, it is triage's duty to pick the option the
    builder proceeds on, record that pick as a decision, and stay accountable