Optimize repository loading and enhance Git UI

Consolidate multiple Git backend calls into a single bundle to reduce
overhead when opening and auto-refreshing repositories. This significantly
improves performance by fetching status, branches, commits, and files
in one optimized operation, instead of re-running 'git rev-parse' and
'git status' multiple times.

Also, streamline commit history loading by fetching file changes inline
via 'git log --name-status -z', eliminating expensive per-commit
'git diff-tree' processes.

Additionally, introduce the ability to create new branches from a
specific commit in the history and refactor the commit comparison
feature into a dedicated dialog. The status panel now displays concise
file names.

.claude/settings.local.json

@@ -23,7 +23,12 @@
       "Bash(npx vite *)",
       "Bash(cargo tree *)",
       "Bash(jobs)",
-      "Bash(npx svelte-check *)"
+      "Bash(npx svelte-check *)",
+      "Bash(git log *)",
+      "Bash(xxd)",
+      "Bash(python3 -)",
+      "Bash(echo \"exit: $?\")",
+      "Bash(grep -n \"input,\\\\|select,\\\\|input {\\\\|select {\\\\|.repo-form input\\\\|input:focus\\\\|::placeholder\" src/app.css)"
     ]
   }
 }