# CC 2.1.132 Adoption — Group A: foundation doc sweep

Four doc additions that document new CC behavior the rest of the codebase already relies on (matrix entries already shipped in v7.84.0). No functional code changes. Closes 4 cc-adoption issues filed by the cron pipeline.

## Issues closed 4 / 19 in the milestone

Issue | Feature | CC | Category
--- | --- | --- | ---
#1639 | enterworktree_branches_from_local_head | 2.1.128 | breaking
#1641 | stale_installed_plugins_path_fix | 2.1.128 | breaking
#1644 | ctrl_r_history_global_default | 2.1.129 | breaking
(no GH issue, gap_score=5) | auto_mode_classifier_error_hint | 2.1.128 | new_field

## Files touched

Path | Change
--- | ---
src/skills/chain-patterns/references/worktree-agent-pattern.md | New "Branch base (CC 2.1.128+)" section — documents that EnterWorktree branches from local HEAD
src/skills/doctor/references/remediation-guide.md | Two new troubleshooting entries: stale plugin paths, auto-mode classifier hints
src/skills/setup/references/keybindings.md | New "CC built-in keys worth knowing" section — Ctrl+R global default, Ctrl+S to scope

## Why doc-only is enough for Group A

All four features are upstream behavior changes that we already gate on via the floor (v7.84.0 raised it to `2.1.132`). The matrix entries in `cc-version-matrix.ts` were added by PR #1623 and the doctor skill already surfaces version-pinned features. What was missing was the human-facing remediation/usage notes that let a maintainer or contributor understand the new behavior when they're reading skill references — not searching the matrix.

## Before / after (worktree-agent-pattern.md)

### Before

    ## Hooks That Fire
    …

    ## Limitations
    - Worktree agents are slightly slower
    - Each worktree is a full copy
    - Merge conflicts possible if agents
      edit same files
    - Don't use for read-only agents

### After

    ## Hooks That Fire
    …

    ## Branch base (CC 2.1.128+)
    EnterWorktree branches from local
    HEAD, not origin/<default-branch>.
    - Unpushed commits preserved
    - No need to push first
    - We floor at 2.1.132 — done.

    ## Limitations
    …unchanged…

## Verification

- ✅ `npm run build` regenerates `plugins/` with the doc updates mirrored
- ✅ `npm run test:skills` — frontmatter + structure unchanged
- ✅ `npm run typecheck` — no source changed
- ✅ No counts moved (skills/agents/hooks unchanged)

Next groups (B–E) handle MCP hygiene, security-adjacent fixes, config behavior, and new distribution surfaces. See the per-group rationale in the chained roadmap.