Two labels.yml files have drifted; docs cite the stale one

[ss-o]

Problem

There are two canonical-label files in this repo, and they have diverged. Every document points at the one the tooling does not read.

	lib/labels.yml	.github/lib/labels.yml
Read by scripts/labels-sync.rb	yes — DEFAULT_LABELS_FILE	no
Cited by AGENTS.md / runbooks / .github/README.md	no	yes, all 8 references
Last substantive update	#451 (Linear transition)	#416
legacy_migrations block	present	absent
sync_policy block	present	absent
dependencies / github_actions automation labels	present	absent

meta:org-tracked carries conflicting descriptions between the two:

• root: Indicates this issue has cross-repository tracking implications (synced to Linear).
• .github/: Auto-add this issue to the org-wide Z-Shell Tracker.

The root copy reflects the post-#451 Linear reality; the .github/ copy still describes the retired GitHub Projects tracker.

Why it matters

The failure is silent. A maintainer follows runbooks/labels.md, edits .github/lib/labels.yml as instructed, runs scripts/labels-sync.rb, and their change has no effect — the script read root lib/labels.yml. Nothing errors, and the dry-run output looks plausible.

The structural blocks are the sharper half: legacy_migrations and sync_policy exist only in root. Anyone treating .github/lib/labels.yml as the source of truth has no legacy-migration table at all, which is precisely the mapping that keeps emoji-suffixed legacy labels from being reintroduced.

History

.github/lib/labels.yml dates to #416. Root lib/labels.yml was then deliberately established by #422 ("restore canonical label source file") and updated again by #451. So the .github/ copy is a stale leftover the documentation was never repointed away from — not a competing authority.

Suggested fix

1. grep for any other consumer of the .github/lib/labels.yml path — workflows, scripts, external automation, or other repos — before removing anything.
2. Delete or symlink .github/lib/labels.yml to the root file.
3. Repoint the 8 documentation references: AGENTS.md:89, .github/README.md:100,136, runbooks/triage.md:26, runbooks/labels.md:7,109,113,181.
4. Consider whether the canonical file belongs at the path the docs already advertise, and move root there instead — either direction works, but only one file should exist.

Also minor: root lib/labels.yml is mode 0600 while the rest of the tree is 0664.

Triage

• Type: bug, area:meta
• Priority: medium — latent, silently wrong, no current breakage
• Effort: small, but requires the consumer audit in step 1 first