renderApprovals had no merge_config_pr case, so those approvals
mis-rendered as generic spawn cards (spawn chip, no sha, 'container will
be created' body). Add a dedicated branch:
- distinct glyph + 'merge-pr' kind chip
- show the reviewed PR-head sha (sha_short), like apply_commit
- a 'review PR on forge' link built from pr_number (now on ApprovalView),
gated on forge_present, mirroring the apply_commit 'commit on forge' link
- no config-diff side-panel (apply_commit-only for now)
History rows get the 'merge-pr' chip too.