fix(gastown): handle empty repos in git-manager to prevent mayor crashes

[jrf0110]

Summary

Fixes empty repository handling in cloudflare-gastown/container/src/git-manager.ts to prevent mayor crashes when connecting repos with zero commits (GitHub issue #1610).

Three functions are hardened:

• cloneRepoInner: Removes --branch <defaultBranch> from git clone (fails on empty repos with "Remote branch not found"). After cloning, detects empty repos via git rev-parse HEAD and creates an initial empty commit with --allow-empty, pushes it, and fetches so origin/<defaultBranch> is available for downstream operations.
• setupBrowseWorktreeInner: Guards against missing origin/<defaultBranch> ref before creating the tracking branch. Returns early with a log message if the ref doesn't exist (e.g., if the push in cloneRepoInner failed).
• createWorktreeInner: Checks HEAD existence before creating branches. Throws a clear error if the repo has no commits.

Verification

• Polecat reports typecheck, lint, and format all pass.
• Code review: validated input sanitization (validateBranchName called before defaultBranch is interpolated into git commands), error handling patterns consistent with existing code, no injection vectors.

Visual Changes

N/A

Reviewer Notes

• The --branch removal from git clone is safe — downstream code already handles branch tracking via origin/<defaultBranch> refs rather than relying on the clone's initial branch.
• The empty commit push uses HEAD:<defaultBranch> refspec so it works even when the local branch name doesn't match the remote default branch.
• All three defensive checks are independently useful: cloneRepoInner prevents the root cause, while setupBrowseWorktreeInner and createWorktreeInner handle the edge case where the initial push fails.

[kilo-code-bot]

Code Review Summary

Status: No Issues Found | Recommendation: Merge

Files Reviewed (1 files)

• cloudflare-gastown/container/src/git-manager.ts

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_{Reviewed by gpt-5.4-20260305 · 341,818 tokens}