[dviejokfs]

Summary

When a deployment for a branch with an open PR/MR moves through created → succeeded/failed, post or update a single sticky comment that reflects the latest state. The comment is keyed by a hidden HTML marker so subsequent updates edit in place rather than spam the PR with new comments.

• New PrCommenter trait + GitPrCommenter impl that dispatches by provider type (GitHub via REST /repos/.../pulls + issue comments, GitLab via REST /merge_requests + notes). Sticky marker is per (project, environment) so multiple Temps envs targeting the same PR each get their own comment.
• New PrCommentListener background task: subscribes to Job::DeploymentCreated / DeploymentSucceeded / DeploymentFailed and calls the commenter with the right phase. Self-contained — uses events the deployments crate already emits, so no wiring changes are needed in temps-deployments.
• Graceful degradation: missing git connection, no open PR, unsupported provider, or 403/401 from the provider (e.g. existing GitHub Apps without pull_requests:write) all log at warn/debug and return Ok. Deployments are never blocked by commenting failures.

What the comment looks like

🚧 Deploying preview

Building commit `abc1234`…

→ on success the same comment becomes:

✅ Preview ready

Commit: `abc1234`

🔗 Open preview

→ on failure:

❌ Preview build failed

Commit: `abc1234`

Scope deliberately kept small

• No new tables, no migrations, no schema changes.
• No new `Job` variants — reuses existing `DeploymentCreated/Succeeded/Failed` broadcasts.
• No per-PR environments. Preview env is whatever environment the deployment already targets.

Known limitations / follow-ups

1. Existing GitHub Apps may lack `pull_requests:write`. The current manifest in `GitProviderFlow.tsx` already requests it for new installs. Old installations hit 403 and are logged at warn level — those users would need to upgrade their app's permissions to get comments. UI nudge for that can be a follow-up.
2. Fork PRs not commented. GitHub's `head=owner:branch` filter only matches same-repo PRs. Temps doesn't deploy fork PRs today so this matches existing behavior.
3. No teardown comment on PR close/merge. The sticky comment stays even after the env URL stops responding. Vercel behaves the same; can be added later if needed.

Test plan

• `cargo check --lib` clean across the workspace (714 crates, 0 errors)
• `cargo test --lib -p temps-git` — 120/120 passing (15 new tests for the PR commenter)
• `cargo clippy --lib -p temps-git --no-deps` — 0 errors
• Unit tests cover: render-body for each phase, marker scoping, GitHub create/edit/no-PR/403 paths, GitLab create/edit/no-MR paths
• Manual smoke test: open a PR in a connected repo, push to it, watch comment appear and update through phases

Related

Companion fix for the branch-delete bug (#1239) lives on a separate branch (`security/0.1.0-hardening`) and isn't bundled here.