fix(git): stop prefixing rtk where it rewrites the output skills parse

The #113 sweep rested on CLAUDE.md's premise that rtk either filters or passes through unchanged,
so prefixing is always safe. Measured against rtk 0.42.4, that premise is false for several of the
commands the sweep prefixed, and two skills were left giving wrong answers silently.

Why:
- `rtk git worktree list --porcelain -z` discards both flags and renders its own format. The
  `locked`/`lock_reason` fields git-worktrees Step 2 must emit are absent entirely, and paths under
  $HOME are abbreviated to `~/`.
- `rtk git branch --list <name>` prints a phantom `* ` line even when nothing matches, so
  git-branches' stated ambiguity test — "output from both means the name is ambiguous" — reported
  every name as ambiguous. `tag --list` is a clean passthrough, so only one half broke.
- `rtk git diff --name-only`/`--name-status` append a `Changes:` trailer to output documented as
  "one per line"; `--word-diff` emits none of the `[-removed-] {+added+}` markers its table
  describes; `rtk git log -L` truncates each line at ~72 chars, on the one command whose purpose is
  showing line content.
- `rtk git stash pop` prints only `FAILED: git stash pop`, swallowing the conflict diagnostic and
  retained-entry message the surrounding prose tells the agent to rely on.

Implementation notes:
- Eleven sites reverted to bare `git`, each carrying its reason inline so the next sweep does not
  undo it. `mergetool` and `rebase -i` are reverted on clause 3's interactive limb only: the TTY
  defect does not reproduce — rtk filters exactly twelve subcommands and execs the rest — and
  ADR-0023 records that measurement rather than a convenient one.
- ADR-0023 states the rule repo-wide with a third clause: a command whose output the skill parses,
  or which is interactive, stays bare. `plugins/git/README.md` is reduced to a pointer; its claim
  that gitea skills "contain no git/rtk mentions at all" was false, and its citation of
  `hard-rules.md` pointed at a file containing no occurrence of "rtk".
- Eight gitea sites swept, all verified byte-identical passthroughs first.
- `scripts/check-rtk-prefix.sh` gates clause 1. Run against main's pre-sweep corpus it reports 99
  findings including every gitea site, so it would have caught the drift #113 was filed about.

Impact: the gate covers clause 1 only, in shell-tagged fences and the opening span of Run cells.
Clause 2 is not gateable — "Run `git switch`" and "`git switch` refuses" are the same tokens — and
prose bullets are invisible to it. Both limits are recorded in gates.md rather than left implied.

Refs: #113
ADR: 0023
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EeH8SCbcrCAQrtymkNuhKP

plugins/git/.apm/skills/git-branches/references/branch-operations.md

@@ -43,9 +43,12 @@ past it: it shelves the working tree and index so the branch pointer can move.
 - **save** — `rtk git stash push -m "<message>"`. Add `-u` to include untracked files; verified on Git
   2.39.5, a plain `push` leaves them in place, and a plain `push` with *only* untracked changes
   reports `No local changes to save` and stashes nothing. Bare `git stash` is `push` with no message.
-- **restore** — `rtk git stash pop` applies the newest entry and deletes it. `rtk git stash apply stash@{n}`
+- **restore** — `git stash pop` applies the newest entry and deletes it. Bare, not `rtk`: on a
+  conflict rtk prints only `FAILED: git stash pop` and swallows the conflict report the paragraph
+  below tells you to read (ADR-0023). `rtk git stash apply stash@{n}`
   applies without deleting, for replaying one shelf onto more than one branch.
-- **list** — `rtk git stash list`; `rtk git stash show -p stash@{n}` prints that entry's diff.
+- **list** — `git stash list` — bare, not `rtk`: rtk prints `No stashes` where git prints nothing,
+  so an empty-output test misfires (ADR-0023). `rtk git stash show -p stash@{n}` prints that entry's diff.
 - **drop** — `rtk git stash drop stash@{n}` deletes one entry. `rtk git stash clear` deletes all of them
   and nothing recovers them — confirm before running it.
 - **branch from a stash** — `rtk git stash branch <branch> stash@{n}` creates a branch at the commit the

plugins/git/.apm/skills/git-branches/references/merging.md

@@ -26,5 +26,6 @@ list the conflicted files, edit each to resolve its markers, then `rtk git add <
 `rtk git merge --continue`.
 
 - `rtk git merge --abort` restores the pre-merge state.
-- `rtk git mergetool` opens the configured merge tool.
+- `git mergetool` opens the configured merge tool — bare, not `rtk`: it hands control to an
+  interactive child process, and a token filter has nothing to offer there (ADR-0023).
 - `rtk git diff --diff-filter=U` shows only the still-conflicted files.