docs(cmd/git): add prose introductions to subcommand pages

why: Make Manager/Cmd pattern usage clear at a glance
what:
- Add Overview section with pattern explanation to all 8 pages
- Include practical code examples for each subcommand
- Reference git man pages (e.g., git-branch(1))
- Note legacy interfaces where applicable (stash, submodule)

Author: tony

docs/cmd/git/branch.md

@@ -2,6 +2,35 @@
 
 For `git-branch(1)`.
 
+## Overview
+
+Manage git branches using {class}`~libvcs.cmd.git.GitBranchManager` (collection-level)
+and {class}`~libvcs.cmd.git.GitBranchCmd` (per-branch operations).
+
+### Example
+
+```python
+from libvcs.cmd.git import Git
+
+git = Git(path='/path/to/repo')
+
+# List all branches
+branches = git.branches.ls()
+
+# List remote branches only
+remote_branches = git.branches.ls(remotes=True)
+
+# Create a new branch
+git.branches.create('feature-branch')
+
+# Get a specific branch and operate on it
+branch = git.branches.get(branch_name='feature-branch')
+branch.rename('new-feature')
+branch.delete()
+```
+
+## API Reference
+
 ```{eval-rst}
 .. autoclass:: libvcs.cmd.git.GitBranchManager
    :members:

docs/cmd/git/notes.md

@@ -2,6 +2,36 @@
 
 For `git-notes(1)`.
 
+## Overview
+
+Manage git notes using {class}`~libvcs.cmd.git.GitNotesManager` (collection-level)
+and {class}`~libvcs.cmd.git.GitNoteCmd` (per-note operations).
+
+### Example
+
+```python
+from libvcs.cmd.git import Git
+
+git = Git(path='/path/to/repo')
+
+# Add a note to a commit
+git.notes.add(object='HEAD', message='This is a note')
+
+# List all notes
+notes = git.notes.ls()
+
+# Get a specific note and operate on it
+note = git.notes.get(object='HEAD')
+note.show()
+note.append(message='Additional info')
+note.remove()
+
+# Prune notes for non-existent objects
+git.notes.prune()
+```
+
+## API Reference
+
 ```{eval-rst}
 .. autoclass:: libvcs.cmd.git.GitNotesManager
    :members:

docs/cmd/git/reflog.md

@@ -2,6 +2,33 @@
 
 For `git-reflog(1)`.
 
+## Overview
+
+Manage git reflog using {class}`~libvcs.cmd.git.GitReflogManager` (collection-level)
+and {class}`~libvcs.cmd.git.GitReflogEntryCmd` (per-entry operations).
+
+### Example
+
+```python
+from libvcs.cmd.git import Git
+
+git = Git(path='/path/to/repo')
+
+# List reflog entries
+entries = git.reflog.ls()
+
+# List entries for a specific ref
+head_entries = git.reflog.ls(ref='HEAD')
+
+# Check if reflog exists for a ref
+git.reflog.exists(ref='main')
+
+# Expire old reflog entries
+git.reflog.expire(ref='HEAD', expire='90.days.ago')
+```
+
+## API Reference
+
 ```{eval-rst}
 .. autoclass:: libvcs.cmd.git.GitReflogManager
    :members:

docs/cmd/git/remote.md

@@ -2,6 +2,33 @@
 
 For `git-remote(1)`.
 
+## Overview
+
+Manage git remotes using {class}`~libvcs.cmd.git.GitRemoteManager` (collection-level)
+and {class}`~libvcs.cmd.git.GitRemoteCmd` (per-remote operations).
+
+### Example
+
+```python
+from libvcs.cmd.git import Git
+
+git = Git(path='/path/to/repo')
+
+# List all remotes
+remotes = git.remotes.ls()
+
+# Add a new remote
+git.remotes.add(name='upstream', url='https://github.com/org/repo.git')
+
+# Get a specific remote and operate on it
+origin = git.remotes.get(remote_name='origin')
+origin.show()
+origin.prune()
+origin.set_url('https://new-url.git')
+```
+
+## API Reference
+
 ```{eval-rst}
 .. autoclass:: libvcs.cmd.git.GitRemoteManager
    :members:

docs/cmd/git/stash.md

@@ -2,6 +2,41 @@
 
 For `git-stash(1)`.
 
+## Overview
+
+Manage git stashes using {class}`~libvcs.cmd.git.GitStashManager` (collection-level)
+and {class}`~libvcs.cmd.git.GitStashEntryCmd` (per-stash operations).
+
+:::{note}
+{class}`~libvcs.cmd.git.GitStashCmd` is the legacy interface. Use `git.stashes`
+({class}`~libvcs.cmd.git.GitStashManager`) for the new Manager/Cmd pattern.
+:::
+
+### Example
+
+```python
+from libvcs.cmd.git import Git
+
+git = Git(path='/path/to/repo')
+
+# Push changes to stash
+git.stashes.push(message='Work in progress')
+
+# List all stashes
+stashes = git.stashes.ls()
+
+# Get a specific stash and operate on it
+stash = git.stashes.get(index=0)
+stash.show()
+stash.apply()
+stash.drop()
+
+# Clear all stashes
+git.stashes.clear()
+```
+
+## API Reference
+
 ```{eval-rst}
 .. autoclass:: libvcs.cmd.git.GitStashManager
    :members:

docs/cmd/git/submodule.md

@@ -2,6 +2,41 @@
 
 For `git-submodule(1)`.
 
+## Overview
+
+Manage git submodules using {class}`~libvcs.cmd.git.GitSubmoduleManager` (collection-level)
+and {class}`~libvcs.cmd.git.GitSubmoduleEntryCmd` (per-submodule operations).
+
+:::{note}
+{class}`~libvcs.cmd.git.GitSubmoduleCmd` is the legacy interface. Use `git.submodules`
+({class}`~libvcs.cmd.git.GitSubmoduleManager`) for the new Manager/Cmd pattern.
+:::
+
+### Example
+
+```python
+from libvcs.cmd.git import Git
+
+git = Git(path='/path/to/repo')
+
+# Add a submodule
+git.submodules.add(url='https://github.com/org/lib.git', path='vendor/lib')
+
+# List all submodules
+submodules = git.submodules.ls()
+
+# Get a specific submodule and operate on it
+submodule = git.submodules.get(path='vendor/lib')
+submodule.init()
+submodule.update()
+submodule.deinit()
+
+# Sync submodule URLs
+git.submodules.sync()
+```
+
+## API Reference
+
 ```{eval-rst}
 .. autoclass:: libvcs.cmd.git.GitSubmoduleManager
    :members:

docs/cmd/git/tag.md

@@ -2,6 +2,35 @@
 
 For `git-tag(1)`.
 
+## Overview
+
+Manage git tags using {class}`~libvcs.cmd.git.GitTagManager` (collection-level)
+and {class}`~libvcs.cmd.git.GitTagCmd` (per-tag operations).
+
+### Example
+
+```python
+from libvcs.cmd.git import Git
+
+git = Git(path='/path/to/repo')
+
+# Create a tag
+git.tags.create(name='v1.0.0', message='Release 1.0.0')
+
+# List all tags
+tags = git.tags.ls()
+
+# Filter tags
+release_tags = git.tags.ls(pattern='v*')
+
+# Get a specific tag and operate on it
+tag = git.tags.get(tag_name='v1.0.0')
+tag.show()
+tag.delete()
+```
+
+## API Reference
+
 ```{eval-rst}
 .. autoclass:: libvcs.cmd.git.GitTagManager
    :members:

docs/cmd/git/worktree.md

@@ -2,6 +2,36 @@
 
 For `git-worktree(1)`.
 
+## Overview
+
+Manage git worktrees using {class}`~libvcs.cmd.git.GitWorktreeManager` (collection-level)
+and {class}`~libvcs.cmd.git.GitWorktreeCmd` (per-worktree operations).
+
+### Example
+
+```python
+from libvcs.cmd.git import Git
+
+git = Git(path='/path/to/repo')
+
+# List all worktrees
+worktrees = git.worktrees.ls()
+
+# Add a new worktree
+git.worktrees.add(path='/path/to/worktree', branch='feature-branch')
+
+# Get a specific worktree and operate on it
+wt = git.worktrees.get(worktree_path='/path/to/worktree')
+wt.lock(reason='Do not delete')
+wt.unlock()
+wt.remove()
+
+# Prune stale worktrees
+git.worktrees.prune()
+```
+
+## API Reference
+
 ```{eval-rst}
 .. autoclass:: libvcs.cmd.git.GitWorktreeManager
    :members: