Fix GitLab fetch failing on GITLAB_HOST mismatch

[dhilgaertner]

Summary

• glab refused to run when Crow's inherited CWD was a git repo whose remote didn't match GITLAB_HOST, aborting IssueTracker.fetchGitLabIssues and three sibling glab calls.
• Fix: add an optional cwd: parameter to the shell helpers in IssueTracker and ProviderManager, and invoke glab from NSHomeDirectory() so its auto-detection finds no conflicting remotes.

Test plan

• make build (clean)
• swift test for top-level (31/31 passing) and CrowProvider package (25/25 passing)
• Manual: launch Crow with at least one GitLab workspace configured while the app's CWD is a GitHub-only repo; verify assigned GitLab issues now render in the sidebar and the fetchGitLabIssues(host:) failed: log line no longer appears.

Closes #195

🤖 Generated with Claude Code

[dgershman]

Code & Security Review

Critical Issues

None.

Security Review

Strengths:

• Uses NSHomeDirectory() as the working directory — a safe, predictable path that avoids information leakage from arbitrary git repos
• No new environment variable handling or user input flows introduced
• The cwd parameter is optional with a nil default, preserving backward compatibility for non-glab callers

Concerns:

• None identified. The change is narrowly scoped to process working directory control.

Code Quality

• The fix is consistent across both files: IssueTracker.swift (3 call sites + 2 shell helper signatures) and ProviderManager.swift (2 call sites + 1 shell helper signature)
• All glab invocations now pass cwd: NSHomeDirectory() — no missed call sites
• The cwd parameter placement (between env: and the variadic args) is clean and follows the existing parameter style
• CrowProvider tests pass (25/25)
• Pre-existing (not this PR): ProviderManager.shell calls waitUntilExit() before readDataToEndOfFile() (L137-138), which can deadlock if output exceeds the 64 KB pipe buffer. IssueTracker.shell already reads-then-waits (fixed in a prior PR). Worth a follow-up but not blocking.

Summary Table

Priority	Issue
🟢 Green	Pre-existing: ProviderManager.shell pipe read order (potential deadlock on large output) — follow-up item

Recommendation: Approve — clean, minimal fix that solves the GITLAB_HOST mismatch by running glab from HOME instead of the app's inherited CWD. No security concerns, consistent implementation, tests pass.