Rename branch-utils to git-utils for broader scope

- Renamed branch-utils.ts to git-utils.ts
- Renamed branch-utils.test.ts to git-utils.test.ts
- Updated imports in main.ts
- Allows for adding other git-related functionality in the future

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: built-by-as

branch-utils.test.ts git-utils.test.tsbranch-utils.test.ts renamed to git-utils.test.ts

@@ -1,4 +1,4 @@
-import {getBranches, sortBranchesWithMainFirst} from './branch-utils';
+import {getBranches, sortBranchesWithMainFirst} from './git-utils';
 import {simpleGit} from 'simple-git';
 
 // Mock simple-git

branch-utils.ts git-utils.tsbranch-utils.ts renamed to git-utils.ts

@@ -10,7 +10,7 @@ import {promisify} from "util";
 import {v4 as uuidv4} from "uuid";
 import {PersistedSession, SessionConfig} from "./types";
 import {isTerminalReady} from "./terminal-utils";
-import {getBranches} from "./branch-utils";
+import {getBranches} from "./git-utils";
 
 const execAsync = promisify(exec);