cmd/git(fix[Git]): Align class annotations with instance variable names

why: Class-level annotations used singular names (remote, branch) but
instance variables used plural names (self.remotes, self.branches),
causing IDE autocomplete confusion.
what:
- Change `remote:` to `remotes:` to match self.remotes
- Change `branch:` to `branches:` to match self.branches
- Add missing annotations: submodules, worktrees, notes, reflog

Author: tony

src/libvcs/cmd/git.py

@@ -25,11 +25,15 @@ class Git:
 
     # Sub-commands
     submodule: GitSubmoduleCmd
-    remote: GitRemoteManager
+    submodules: GitSubmoduleManager
+    remotes: GitRemoteManager
     stash: GitStashCmd  # Deprecated: use stashes
     stashes: GitStashManager
-    branch: GitBranchManager
+    branches: GitBranchManager
     tags: GitTagManager
+    worktrees: GitWorktreeManager
+    notes: GitNotesManager
+    reflog: GitReflogManager
 
     def __init__(
         self,