ci: Review PRs per-commit and attach comments to correct commits

ci: Review PRs per-commit and attach comments to correct commits

Switch claude-review from reviewing the entire PR diff at once to
reviewing each commit individually via subagents. Each commit review
subagent receives the PR context, preceding commit diffs, and its own
commit diff, then returns comments tagged with the commit SHA. This
ensures review comments are attached to the correct commit via the
GitHub API rather than all pointing at HEAD.

Also add Bash(gh:*) to allowed tools so subagents can fetch per-commit
diffs via `gh api` without needing local git objects, and remove CI
analysis (needs to be delayed until CI finishes to be useful).

Co-developed-by: Claude Opus 4.6 <noreply@anthropic.com>