refactor(ci): split api-reference sync into three focused jobs (#677)

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

.github/templates/docs/guide-references-issue.md

@@ -0,0 +1,24 @@
+<!-- drift-type:cross-site-refs -->
+<!-- trigger-prs:{{TRIGGER_PR_NUMBERS}} -->
+<!-- apis:{{CHANGED_API_NAMES}} -->
+
+## Summary
+Pages outside `/reference/` mention APIs that changed in a recent PR. These references may be stale and need human triage.
+
+## References
+- Triggering PR(s): {{SOURCE_PR_URLS}}
+
+## Stale References Found
+| File | Line(s) | Stale Reference | API Change | Confidence | Action |
+|---|---|---|---|---|---|
+{{STALE_REFERENCES_TABLE_ROWS}}
+
+### Directories Checked
+- `site/src/content/docs/concepts/`
+- `site/src/content/docs/how-to/`
+- `packages/*/README.md`
+
+## Notes
+- **Confidence levels**: `high` = definitely stale, `medium` = likely stale, `low` = needs human review.
+- All items in this issue need human triage — false positives are possible.
+- Related APIs are grouped into a single issue when they affect the same files.