chore(source-control): document plugin as sole worktree-convention SSOT (#401)

plugins/source-control/.claude-plugin/plugin.json

@@ -1,7 +1,7 @@
 {
   "$schema": "https://json.schemastore.org/claude-code-plugin-manifest.json",
   "name": "source-control",
-  "version": "0.26.2",
+  "version": "0.26.3",
   "description": "Git and GitHub delivery workflow: /commit (Conventional Commits + Co-Authored-By trailer via safe heredoc mechanics), /pull-request (prep, create, CI monitoring, review-comment triage, merge, CI-log fetch), /babysit-prs (self-pacing fleet loop — safe by default; opt-in worker/autopilot tiers add gate-checked merge and thread resolution behind a deterministic Python engine), /babysit-loop (the loop-lane merge lane: a standing or drain loop that invokes babysit-prs per cycle, configured through repo-scoped babysit_loop_* keys on the layered source-control.md seam, with merge authority human-only until the target repo's tracked config adopts the lane, a gate-proven C2-mechanical baseline once adopted, and merge-rung raises binding from the team-tracked layer only), /worktree (create, status, cleanup, audit for parallel-session isolation), /setup (check the effective commit-subject / PR-title convention merged across its config layers and the babysit-prs config, or apply — interview the repo and write the convention config to a chosen layer), and /resolve-conflicts (intent-first merge/rebase conflict resolution with a semantic-conflict sweep — never --abort). The commit-subject / PR-title convention is configurable via a source-control.md config written by a re-runnable setup skill, layered across a ~/.claude user-global file, the tracked team file, and a gitignored .claude/source-control.local.md personal overlay merged per key; Conventional Commits is the default when no convention is declared.",
   "author": {
     "name": "Melodic Software",

plugins/source-control/CHANGELOG.md

@@ -3,6 +3,19 @@
 All notable changes to the `source-control` plugin are documented here. Format follows
 [Keep a Changelog](https://keepachangelog.com/en/1.1.0/); this plugin uses semantic versioning.
 
+## [0.26.3]
+
+### Changed
+
+- **The plugin is now the canonical, sole source for the worktree conventions (#401).** The
+  `babysit-prs` skill's `reference/worktrees.md` states it owns the ephemeral babysit-worktree
+  exemption (lease-scoped cleanup, never a global open-PR prune — machine-enforced by
+  `prune_babysit_worktrees.py`) and that rooting those worktrees outside a repository's discoverable
+  tree keeps them out of enumeration such as `ghq list`; the `worktree` skill states it owns the
+  parallel-session external-root convention going forward. Both close the SSOT gap left by the
+  retired external `ghq-layout-sibling-pr-worktrees` prose doc (physical deletion of that doc is a
+  separate follow-up in the dotfiles repo).
+
 ## [0.26.2]
 
 ### Fixed

plugins/source-control/skills/babysit-prs/reference/worktrees.md

@@ -9,6 +9,12 @@ key's resolved value and its unset fallback; `<worktree-root>` defaults to the `
 subdirectory of the plugin data directory, and `<state-dir>` is its `state/babysit-prs`
 subdirectory.
 
+This file is the canonical, sole source for the babysit ephemeral-worktree convention — the
+plugin owns it, not any external prose doc. Rooting these worktrees outside every repository's
+discoverable tree (the plugin data directory by default) is deliberate: it keeps ephemeral
+scratch out of repository enumeration such as `ghq list`. Repointing `babysit_worktree_root`
+back under a discoverable tree reintroduces that pollution.
+
 ## Policy
 
 - At the start of a queue run holding the queue lease, remove only unleased clean babysit

plugins/source-control/skills/worktree/SKILL.md

@@ -20,6 +20,8 @@ Orchestrate git worktree lifecycle from creation through cleanup. **Front-half**
 
 **Why this exists:** worktrees are the isolation mechanism for parallel code changes — multiple Claude Code sessions on different tasks without stepping on each other. In repos where branch protection blocks direct commits to main, every feature, fix, or refactor starts with a worktree or branch; this skill makes that seamless.
 
+This skill is the canonical owner of the parallel-session worktree convention going forward — no external prose doc. Worktrees live at an external `worktree_root` (`<root>/<owner>-<repo>-<slug>`, outside every repository), never nested inside any repository's tree — that nesting invariant is what creation enforces (the abandoned sibling-layout convention re-triggered the #400 double-load bug). Keeping `worktree_root` clear of repository-discovery roots (such as a ghq root) is convention, not machine-checked: creation rejects only paths inside an existing repository, and a discovery-root placement would pollute repository enumeration the same way the sibling layout did — choose the root accordingly.
+
 ## Adapting to your environment (graceful degrade)
 
 This skill is self-contained — every action runs on plain `git`, plus `gh` for PR cross-referencing where available. Where it mentions an adjacent capability (an issue tracker, a build/lint verifier, a session-start setup hook), treat it as optional: use it when your environment provides it, proceed without it otherwise. Project-specific conventions — branch naming, worktree layout, which gitignored files a fresh worktree needs — come from the consuming project's own `CLAUDE.md`, rules, and hooks; read them before creating or removing anything.