fix(labels): never name a label the repo lacks; a stale round owes an ask too

Round 1 review (claude-bot, codex-bot on #138 and the sibling PRs).

gh issue edit rejects the WHOLE call on one unknown label name, and this
change made state and blockers share a single edit for anti-flicker. On a repo
whose taxonomy predates the blocker:* labels -- every repo, at merge -- the
first sweep would therefore converge NOTHING on exactly the PRs the change
exists to fix, surfacing only as a warning in a cron log. Adds are now
filtered against the repo's real label set, read once per sweep. Removals need
no filter: they are built from has_label, so they provably exist. An
unreadable label set does not filter, because a failed read must not silently
strip the board.

blocker:unrequested also missed the stale round. MISSING and STALE are both
verdicts this head does not have -- nobody reviewed it, or everybody reviewed
something else -- and the agent owes an ask either way. The stale one is the
worse of the two: it has approvals on the page that no longer describe the
tree, which is the case LABELS.md already called the most dangerous.

Fixtures 66 -> 68.

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

.github/scripts/labels-reconcile.sh

@@ -194,12 +194,17 @@ blockers() { # → the blocker:* labels this PR should carry, one per line
   # explicit human request — a maintainer claiming a PR early is deliberate,
   # not a dropped ball.
   if [ "$DRAFT" != true ] && ! requested "$HUMAN"; then
-    local b any_missing=false any_requested=false
+    local b v owed=false any_requested=false
     for b in "${BOTS[@]}"; do
       requested "$b" && any_requested=true
-      [ "$(bot_verdict "$b")" = MISSING ] && any_missing=true
+      # MISSING and STALE are both verdicts this head does not have: nobody
+      # reviewed it, or everybody reviewed something else. The agent owes an
+      # ask either way — the stale round is if anything the worse of the two,
+      # since it has approvals on the page that no longer describe the tree.
+      v="$(bot_verdict "$b")"
+      case "$v" in MISSING | STALE) owed=true ;; esac
     done
-    if [ "$any_missing" = true ] && [ "$any_requested" = false ]; then
+    if [ "$owed" = true ] && [ "$any_requested" = false ]; then
       echo blocker:unrequested
     fi
   fi
@@ -350,6 +355,30 @@ reconcile_pr() { # $1 = PR number; relies on the globals set from its fetch
   done
   add="${add#,}"
   remove="${remove#,}"
+
+  # Never NAME a label the repo does not have. `gh issue edit --add-label`
+  # rejects the WHOLE call on one unknown name — nothing is applied — so a
+  # single missing blocker would take the state convergence down with it, on
+  # exactly the PRs this change exists to fix, surfacing only as a log line.
+  # Batching state and blockers into one edit for anti-flicker is what widened
+  # that blast radius; filtering the add side is what closes it again.
+  # Removals need no filter: they are built from has_label, so the label
+  # provably exists. REPO_LABELS unreadable means no filtering rather than
+  # filtering everything out — a failed read must not silently strip the board.
+  if [ -n "${REPO_LABELS:-}" ]; then
+    local kept="" missing="" want
+    for want in ${add//,/ } "$desired"; do
+      [ "$want" = "$desired" ] && continue
+      if grep -qxF "$want" <<<"$REPO_LABELS"; then kept="$kept,$want"
+      else missing="$missing $want"; fi
+    done
+    add="${kept#,}"
+    if ! grep -qxF "$desired" <<<"$REPO_LABELS"; then
+      log "#$n: WARNING: state label '$desired' does not exist — run the workflow manually to bootstrap"
+      return
+    fi
+    [ -n "$missing" ] && log "#$n: WARNING: missing label(s)$missing — state still converged; dispatch the workflow to bootstrap"
+  fi
   if ! has_label "$desired" || [ -n "$remove" ] || [ -n "$add" ]; then
     args=(--add-label "$desired${add:+,$add}")
     [ -n "$remove" ] && args+=(--remove-label "$remove")
@@ -404,6 +433,11 @@ main() {
     bootstrap_labels
   fi
 
+  # The repo's label set, read ONCE per sweep — reconcile_pr filters every
+  # add against it, because one unknown name fails the whole edit call.
+  REPO_LABELS="$(gh label list -R "$REPO" --limit 200 --json name --jq '.[].name' 2>/dev/null || echo "")"
+  [ -z "$REPO_LABELS" ] && log "WARNING: could not read the label set — applying labels unfiltered"
+
   local n
   for n in $(gh pr list -R "$REPO" --state open --limit 100 --json number --jq '.[].number'); do
     (

CHANGELOG.md

@@ -33,7 +33,13 @@ which records not just what changed but what each drill run proved.
   human request — a maintainer claiming a PR early is deliberate.
 
   The reconciler strips `state:needs-rebase` on sight, so the retirement heals
-  the board rather than stranding a label nothing recomputes. Fixtures 51 → 64.
+  the board rather than stranding a label nothing recomputes. It also never
+  *names* a label the repo does not have: `gh issue edit` rejects the whole
+  call on one unknown name, so on a repo whose taxonomy predates this change
+  an unbootstrapped `blocker:*` would otherwise take the state convergence
+  down with it, on exactly the PRs the change exists to fix. Adds are filtered
+  against the repo's real label set and the shortfall is logged.
+  Fixtures 51 → 66.
 
 - **The tenant templates carry rig's family suffix: `claude` → `claude-box`,
   `codex` → `codex-box`, `grok` → `grok-box`, `staging` → `staging-box`**

LABELS.md

@@ -16,7 +16,7 @@ single reply, and a human takes the final review.
 |---|---|---|---|---|
 | `state:building` | `#FBCA04` | the coding agent, still building | PR opened as draft | marked ready + bot reviews requested |
 | `state:bots-reviewing` | `#1D76DB` | the reviewer bots to finish the round | ready with reviews requested, or fixes pushed and reviews re-requested | all three bots have reviewed the round |
-| `state:addressing` | `#D93F0B` | the coding agent to reply, fix, or ask | all bots reviewed and not all approved; or nobody was asked; or a blocker is up | the thing the blocker names is done |
+| `state:addressing` | `#D93F0B` | the coding agent to reply, fix, or ask | all bots reviewed and not all approved; or nobody was asked; or a blocker is up | the round-reply is posted and fixes pushed — and any blocker named alongside is cleared |
 | `state:needs-human` | `#8250DF` | the human reviewer | the PR **could be merged right now**: no blockers, three formal head-current approvals — and the human review is requested | merged — or changes requested, which cycles back to `state:addressing` |
 
 `bots-reviewing` and `addressing` are deliberately distinct: staleness in the
@@ -35,7 +35,7 @@ PR carries as many as apply.
 |---|---|---|---|
 | `blocker:conflict` | `#B60205` | GitHub says `CONFLICTING` — the agent owes a **rebase** | it merges cleanly |
 | `blocker:ci-red` | `#B60205` | a check failed — the agent owes a **fix**, which a rebase will not provide | checks are green |
-| `blocker:unrequested` | `#E99695` | somebody still owes a verdict and **nobody was asked** for one | reviews are requested |
+| `blocker:unrequested` | `#E99695` | this head has no verdict from somebody — never reviewed, or staled by a push — and **nobody was asked** for one | reviews are requested |
 
 One rule joins the axes: **`state:needs-human` requires zero blockers.** Any
 blocker means the work is the agent's, whatever the review round says.

test/labels-reconcile.sh

@@ -201,7 +201,17 @@ expect "ready, nobody asked, nothing reviewed raises unrequested" blocker:unrequ
 # ...the partial case is equally stalled: one verdict in, nobody asked for the rest
 REVIEWS_JSON="$(reviews "$(rev "$BOT1" APPROVED head1 "" t1)")"
 expect "one bot in, none requested is still unrequested" blocker:unrequested "$(blockers)"
+# ...a STALE round with nobody asked is the same debt, and arguably worse: the
+#    page carries approvals that no longer describe the tree. Guarding on
+#    MISSING alone let this one through with no blocker at all.
+REVIEWS_JSON="$(reviews \
+  "$(rev "$BOT1" APPROVED oldhead "" t1)" \
+  "$(rev "$BOT2" APPROVED oldhead "" t2)" \
+  "$(rev "$BOT3" APPROVED oldhead "" t3)")"
+expect "a stale round with nobody asked is unrequested too" blocker:unrequested "$(blockers)"
+expect "...and is still the agent's ball" state:addressing "$(decide_state)"
 # ...but a live request means an answer IS coming
+REVIEWS_JSON="$(reviews "$(rev "$BOT1" APPROVED head1 "" t1)")"
 REQUESTED="$BOT2"
 expect "a live bot request is not a stalled round" "" "$(blockers)"
 # ...and a draft is exempt: the bots ignore drafts by design