refactor(git): normalize rtk-prefix usage, add metadata.version

Two bundled fixes across the same nine skills, since both touch the
same files.

Issue #113: skill prose used rtk git and bare git inconsistently for
the same operations, with no stated rule for which applied where.
Executable instructed commands (a dispatch-table "Run" cell, a fenced
code-block procedure, an imperative step) now consistently use rtk
git; illustrative or referential mentions -- naming a flag's behavior,
quoting a doc heading, warning against an anti-pattern -- stay bare
git. Documented in the new plugins/git/README.md, scoped to this
plugin only: gitea-* skills talk to the server over MCP tools and
carry no git/rtk mentions at all.

Also the git-plugin slice of #127: metadata.version added to the
eight skills that lacked it. git-commits already had one and is
untouched.

Fixes: #113
Fixes: #127
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EeH8SCbcrCAQrtymkNuhKP

plugins/git/.apm/skills/pc-run/SKILL.md

@@ -8,6 +8,7 @@ description: >
 compatibility: Requires pre-commit installed and available on PATH.
 
 metadata:
+  version: "1.0.0"
   category: devtools
   source_keys:
     - context7-pre-commit-com
@@ -20,7 +21,7 @@ allowed-tools: Bash Read
 
 - The `SKIP` env var takes exact hook `id` values, comma-separated with no spaces: `SKIP=check-yaml,gitleaks git commit -m "msg"`. A space after a comma silently skips nothing instead of erroring.
 - Never bypass a failing hook with `git commit --no-verify` (or `-n`). Hooks are the automated QA gate, so a bypassed commit pushes the failure downstream where it costs more — diagnose it instead.
-- `- files were modified by this hook` is not a bug. A fixer hook rewrote a staged file, so the staged snapshot is stale and the commit is blocked on purpose. Re-stage and re-run the same commit: `git add -u && git commit`. Do NOT reach for `pre-commit install -f` here — it overwrites `.git/hooks/` and has nothing to do with re-staging.
+- `- files were modified by this hook` is not a bug. A fixer hook rewrote a staged file, so the staged snapshot is stale and the commit is blocked on purpose. Re-stage and re-run the same commit: `rtk git add -u && rtk git commit`. Do NOT reach for `pre-commit install -f` here — it overwrites `.git/hooks/` and has nothing to do with re-staging.
 
 ## Gate — `pre-commit clean`