fix(git): correct three command claims the plugin got wrong, and give rebase an owner

Three statements were false against the git in use (2.39.5), each verified by
running it.

`git rebase --autosquash HEAD~N` without `-i` is a silent no-op: git prints
"Successfully rebased", the `fixup!` commit survives with the same SHA, and
rewrite-history.md presented that as the preferred flow with `-i` as an optional
review step. The agent reports the squash as done and the `fixup!` subject then
trips this repo's own commit-msg gate. `-i` is now the command, not the alternative.

"Fetch never modifies a local branch, so it is always safe to run" — new text on
this branch — is false: `git fetch origin main:probe` fast-forwarded the local
branch, and a `+` prefix force-updates it, losing commits. The claim is scoped to
the no-refspec form.

`git worktree add --orphan` does not exist before Git 2.42; on 2.39.5 it is
`error: unknown option 'orphan'`, exit 129. The same file gives a version floor for
`--recurse-submodules` three sections earlier. Floor added, with a fallback that
was tested before being documented.

git-workflow claimed "every request resolves to exactly one of these six" while
rebase, reset and stash were owned by no skill — `git reset` appeared nowhere in
the plugin, old tree or new — so "undo my last commit" routed nowhere. The claim is
gone, the router gains rows for all three, and the procedures now exist: plain
rebase with `--onto` and conflict handling, a reset mode table gated on `--hard`,
and stash save/pop/list/drop. `--hard` gets an always-loaded Gotcha, matching the
register the force-push refusal already sets.

Cherry-pick had three claimants pointing at git-history while git-commits owned the
flow, and the two copies were not equivalent — git-history's lacked the destination
check, the rtk prefix and `--abort`. Resolved to git-commits per #112; the weaker
duplicate is replaced by a hand-off.

git-commits' metadata.version was deleted rather than bumped in 14af50b, leaving two
house-contract documents citing a worked v0.1.2 to v0.1.3 transition against a file
declaring no version. Restored to 0.1.3.

Also: the divergent-pull explanation stated a `--ff-only` default that does not
exist (it is a hard error); `--remote` "requires" a configured branch where it uses
one; `git push origin --delete` moved to git-remotes, which owns the remote-side
gates; seven retired `git:<name>` source slugs; git-orchestrate quoted a
git-workflow sentence that no longer exists; git-submodules regains the indirect
trigger that made "add a dependency repo" routable; and commit atomicity is a common
gate rather than reachable only from the create flow.

Refs: #112, #113

plugins/git/.apm/skills/git-remotes/references/fetch.md

@@ -7,7 +7,9 @@ source_keys:
 
 # Fetching
 
-Fetch updates remote-tracking branches (`refs/remotes/<name>/*`) and never modifies a local branch, so it is always safe to run.
+Fetch **with no refspec** updates remote-tracking branches (`refs/remotes/<name>/*`) and leaves every local branch alone.
+
+That safety comes from the default refspec, not from `fetch` itself. Give it an explicit one and it writes to local branches: verified on Git 2.39.5, `git fetch origin main:probe` fast-forwarded the local `probe` branch, and a `+` prefix force-updates the destination, discarding whatever commits it held. Treat any `fetch` carrying a `<src>:<dst>` refspec as a branch update, not a read.
 
 - **One remote**: `git fetch <remote>` — all branches
 - **One branch**: `git fetch <remote> <branch>` — the result lands in `FETCH_HEAD`, not a tracking ref

plugins/git/.apm/skills/git-remotes/references/pull.md

@@ -23,9 +23,11 @@ A pull that diverges with no strategy configured fails, and that failure is the
 
 ## Config precedence
 
-The installed default varies by Git version — older versions merge on divergence, newer ones
-default to `--ff-only` — so an unset `pull.ff` means the same pull behaves differently on different
-machines. Set it explicitly.
+`--ff-only` is not Git's default on an unset config, and never has been. Older versions silently
+merged on divergence; current ones refuse outright — verified on Git 2.39.5, a divergent pull with
+nothing configured prints the reconciliation hint and exits 128 with
+`fatal: Need to specify how to reconcile divergent branches.` The behaviour therefore still varies
+by installed version, and neither variant is the one you want. Set it explicitly.
 
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