M132 Group H — CC 2.1.133 effort + skill discovery (FINAL group)

Completes M132 (CC 2.1.133 adoption). 3 issues, doc adoption + matrix entries + hooks README note. After this lands, M132 is 11/11 (100%).

Issues closed

#	Slug	What it fixes / adds
1702	hooks-effort-level-input	NEW: hooks receive `effort.level` JSON input field + `$CLAUDE_EFFORT` env var (also in Bash tool)
1708	effort-cross-session-leak-fix	FIXED: `/effort` in one session no longer changes other concurrent sessions; IDE effort changes no longer silently dropped
1709	subagent-skill-discovery-fix	FIXED: subagents (via Task tool) now discover project/user/plugin skills as documented

#1702 — 188 hooks in src/hooks/ can now branch on effort without parsing JSON input. quality-gates skill benefits directly.
#1708 — Chain-patterns multi-worktree flows are stable; concurrent sessions are isolated.
#1709 — Agent-orchestration patterns (ork:implement, ork:fix-issue, etc.) that spawn subagents now work as documented; if subagents claimed "skill not found", that was the bug.

src/skills/configure/references/cc-version-settings.md — 3 new subsections under existing ## CC 2.1.133 Settings
src/hooks/README.md — callout: hooks can read $CLAUDE_EFFORT directly (2.1.133+)
src/hooks/src/lib/cc-version-matrix.ts — 3 new entries
src/hooks/src/__tests__/lib/cc-version-matrix.test.ts — count assertions bumped +3 (matrix grows from 400 → 403)
plugins/ mirror + docs/site MDX regen

vitest cc-version-matrix.test.ts  64/64 PASS

After this PR merges:

M132 (CC 2.1.133 adoption)  11/11 closed  (100%)
  Group F  4 issues  shipped
  Group G  4 issues  shipped
  Group H  3 issues  shipping NOW