chore(sync): cascade CLAUDE.md fleet/partial/unique skill vocabulary

Adopts canonical's new 'Skill scope: fleet vs partial vs unique'
section + 'updating' umbrella explanation + fleet-skill runner
quick-reference.

Author: jdalton

CLAUDE.md

@@ -163,6 +163,30 @@ Full hook spec in [`.claude/hooks/token-guard/README.md`](.claude/hooks/token-gu
 - `/quality-scan` — quality analysis
 - Shared subskills in `.claude/skills/_shared/`
 
+#### Skill scope: fleet vs partial vs unique
+
+Every skill under `.claude/skills/` falls into one of three tiers — surface this distinction when adding a new skill so it lands in the right place:
+
+- **Fleet skill** — present in every fleet repo, identical contract everywhere. Examples: `path-guard`, `quality-scan`, `security-scan`, `updating`, `programmatic-claude-lockdown`, `promise-race-pitfall`. New fleet skills land in `socket-repo-template/template/.claude/skills/<name>/` and cascade via `node socket-repo-template/scripts/sync-scaffolding.mts --all --fix`. Track them in `SHARED_SKILL_FILES` in the sync manifest.
+- **Partial skill** — present in the subset of repos that need it, identical contract within that subset. Examples: `cursor-bugbot` (every repo with PR review), `updating-xport` (every repo with `xport.json`), `squashing-history` (repos with the squash workflow). Live in each adopting repo's `.claude/skills/<name>/`. When you change one, propagate to the others.
+- **Unique skill** — one repo only, bespoke to that repo's domain. Examples: `updating-cdxgen` (sdxgen), `updating-yoga` (socket-btm), `release` (socket-registry). Never canonical-tracked; the host repo owns it end-to-end.
+
+Audit the current classification with `node socket-repo-template/scripts/run-skill-fleet.mts --list-skills`.
+
+#### `updating` umbrella + `updating-*` siblings
+
+`updating` is the canonical fleet umbrella that runs `pnpm run update` then discovers and runs every `updating-*` sibling skill the host repo registers. The umbrella is fleet-shared; the siblings are per-repo (or partial — e.g. `updating-xport` lives in every repo with `xport.json`). To add a new repo-specific update step, drop a new `.claude/skills/updating-<domain>/SKILL.md` and the umbrella picks it up automatically — no edits to `updating` itself.
+
+#### Running skills across the fleet
+
+`scripts/run-skill-fleet.mts` (in `socket-repo-template`) spawns one headless `claude --print` agent per fleet repo, in parallel (concurrency 4 by default), with the four lockdown flags set per the *Programmatic Claude calls* rule above. Per-skill profile table maps known skills to sensible tool/allow/disallow lists; override with `--tools` / `--allow` / `--disallow`. Per-repo logs land in `.cache/fleet-skill/<timestamp>-<skill>/<repo>.log`. Use `Promise.allSettled` semantics — one repo's failure doesn't abort the rest.
+
+```bash
+pnpm run fleet-skill updating                     # update every fleet repo
+pnpm run fleet-skill quality-scan --concurrency 2 # slower, more conservative
+pnpm run fleet-skill --list-skills                # classify skills fleet/partial/unique
+```
+
 <!-- END FLEET-CANONICAL -->
 
 ## USER CONTEXT