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/git-remotes/SKILL.md

@@ -10,6 +10,7 @@ description: >
   Not submodule pointers -> `git-submodules`.
 
 metadata:
+  version: "1.0.0"
   category: git
   source_keys:
     - git-scm-remote-docs
@@ -27,7 +28,7 @@ metadata:
 
 ## Step 1 — Clear the force-push gate
 
-`main` and `master` are a hard refusal: decline a force-push targeting either, whatever confirmation accompanies it, because no local approval can restore what the remote loses. On any other branch, `git push --force` and `-f` run only after the caller passes `confirm: true` for that specific push — for a human caller, prompt instead of failing.
+`main` and `master` are a hard refusal: decline a force-push targeting either, whatever confirmation accompanies it, because no local approval can restore what the remote loses. On any other branch, `rtk git push --force` and `-f` run only after the caller passes `confirm: true` for that specific push — for a human caller, prompt instead of failing.
 
 ## Step 2 — Dispatch