refactor(github): drop dead CommentList field from ghIssue

[itsmiso-ai]

Removes unpopulated CommentList field from ghIssue and updates shouldComment to check Comments count directly.

Fixes #98

Opened by foreman on review GO (workload wl-misospace-alert-triage-98).

[its-saffron]

AI Automated Review

Full PR review.

Analysis engine: MiniMax-M2.7@https://litellm.jory.dev/v1 (anthropic) — primary route

Review Summary

Recommendation: Approve.

This PR cleanly removes a dead field from github.go and simplifies the shouldComment gate as requested in issue PR 98.

Change Analysis

The diff is minimal and surgical:

1. ghIssue struct — CommentList []ghIssueComment removed (tagged json:"-", was never populated)
2. ghIssueComment type — removed entirely (was unreferenced after the field removal)
3. shouldComment function — reduced from len(existing.CommentList) == 0 && existing.Comments == 0 to existing.Comments == 0

The reduced condition is semantically equivalent to the original: CommentList was always empty (never assigned), so len(existing.CommentList) == 0 was a constant-true guard. The Comments field from the GitHub API already provides the correct first-comment count.

Linked Issue Fit

Issue PR 98 acceptance criteria are fully satisfied:

• ✅ ghIssue.CommentList removed
• ✅ ghIssueComment type removed
• ✅ shouldComment rewritten as if existing.Comments == 0 { return true }
• ✅ Only github.go changed (10 additions, 15 deletions, net -5 lines)

Standards Compliance

No repository standards are violated:

• No new dependencies introduced — purely a removal refactor
• Go conventions followed — struct fields cleaned up consistently
• Comments preserved — the shouldComment comment explaining the first-fire gate remains intact
• File scope respected — changes confined to github.go as the issue specified

CI Results

Both checks passed:

• test — success
• docker — success

Findings

No blockers, majors, or minors identified.