fix(git): restore router coverage and commands the retrofit dropped

git-workflow calls itself a router but named two of the six domains it routes to;
the other four appeared nowhere in the file. All six are now named, with a
routing table in the always-loaded body.

git-submodules lost the foreach shell-variable semantics -- only the bare names
survived, though $sm_path and $displaypath differ solely by which directory you
are in. The table is back. Its relocated commands had also dropped the rtk git
prefix its own SKILL.md mandates; 24 of them are re-prefixed. The wider rtk
inconsistency across the plugin stays with #113.

Also restores git-commits' body and footers output fields, git-branches' tag/
branch detection commands, git-worktrees' git config --worktree, pc-run's
ambiguity fallback, git-remotes' git-history boundary, and git-history's pickaxe
triggers.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EJJrm5YmacbwMdzZpXcoti

plugins/git/skills/git-branches/SKILL.md

@@ -20,7 +20,7 @@ metadata:
 ## Gotchas
 
 - **Uncommitted changes abort a switch.** `git switch` refuses rather than clobbering conflicting local edits. Offer to stash and retry — forcing the checkout past it is how work disappears.
-- **A branch and a tag can carry the same name.** Prefer `git switch` over `git checkout`, and where a command accepts either ref, disambiguate with `refs/heads/<name>` or `refs/tags/<name>`.
+- **A branch and a tag can carry the same name.** Detect it before acting — `git branch --list <name>` and `git tag --list <name>`; output from both means the name is ambiguous. Prefer `git switch` over `git checkout`, and where a command accepts either ref, disambiguate with `refs/heads/<name>` or `refs/tags/<name>`.
 - **`main` and `master` are a refusal, not a gate.** Force-pushing, force-deleting, or renaming them is rejected even when the caller passes `confirm: true` — no flag makes the remote's history recoverable. Offer a new branch instead.
 
 ## Step 1 — Determine the branching pattern