feat(effort): entry level on every skill next to its model pin (BDR-108)

- lib/effort-pins.txt (map) + lib/effort-pins.sh (idempotent re-apply)
  replace the hardcoded brainstorming/writing-plans loop; called after the
  last vendoring step of install-plugins.sh AND update-all.sh (the resync
  dropped the pins until the next make plugin)
- design stack high uniform (last loaded wins), superpowers, agent-skills,
  21st pack pinned from the map; skills-perso low, pdf-translate medium,
  site-motion high
- doctrine: design stack loads paired with the first Read; one level per
  stack (CLAUDE.global.md, lib/effort-shift.md)
- lib/effort-audit.py prints thinking coverage per scope (sub-agent records
  carry no thinking count on ~94 % of requests)
- census map-driven + fixture suite lib/tests/effort-pins.test.sh; docs
  README/USAGE/CHANGELOG; contract + TODO plan

CLAUDE.global.md

@@ -283,6 +283,9 @@ design routing; the design-toolchain hook reinforces it.
 - Design system / brand → design-consultation first, then the build tools.
 - Review / audit → design-review + emil-design-eng + design-motion-principles
   + /impeccable audit|critique + `impeccable detect` floor.
+- Load the stack paired with the first Read of the target file, never
+  alone (a lone Skill call applies no effort, `lib/effort-shift.md`); every
+  member pins `high`, one level per stack (`lib/effort-pins.txt`).
 Scope doubt → ask or default to Build, never silently skip. Gate: light
 skills run `~/.claude/lib/design-gate.md`, orchestrators plugin-check. 21st =
 CLI (`npm i -g @21st-dev/cli`, `21st login`), no MCP, no key; search free,