Nil pointer panic (SIGSEGV) when switching to bare repo / worktree with .git pointer via recent-repos menu (<c-r>)

### Describe the bug

When I start lazygit outside of any git repository, it immediately starts consuming very high CPU (often 400%+) and keeps increasing RAM usage significantly.

cd into a folder that is not a git repository.
Run lazygit
Observe high CPU usage (400%+) and steadily rising memory usage.
### To Reproduce
Steps to reproduce the behavior:

### Expected behavior

Lazygit should either:

Show a clean error message like "must be run in a work tree", or
Gracefully skip / handle bare repos in the switch path.

### Screenshots

### Version info:
lazygit --version

###version=0.62.2

commit=v0.62.2,
build date=2026-06-04T09:11:05Z,
build source=binaryRelease,
version=0.62.2,
os=linux [ Arch Linux ( profile -> Minimal ) ],
arch=amd64,
git version=2.54.0

### Terminal info:

DWM -> ST terminal

Start by reproducing the issue from a non-repository directory, then trace the recent-repositories menu switch path described in the title. Check how bare repositories and worktrees with a .git pointer are handled, and verify that switching either produces a clean error or skips the invalid entry without CPU or memory growth.

Written by the indexing model from the issue text.