[Bundle test] Step 1: build schema

[kiki830621]

Test child 1 of bundle dogfood (parent #22). First in ordered chain — no Blocked-by.

[kiki830621]

Closing dogfood test issue.

Bundle flag verification (#21 v2.52.0 apply phase) covered:

• 5.1 Epic [Epic] Bundle flags dogfood test (v2.52.0 verification) #22 + 3 children [Bundle test] Step 1: build schema #23-[Bundle test] Step 3: add UI #25 created with task list + Blocked-by chain ✓
• 5.2 GitHub renders task list - [ ] #N as sub-issues with progress bar ✓
• 5.3 GraphQL Layer 1 mutation failed → Layer 2 body blockquote > Blocked by #M persisted (graceful degradation verified) ✓
• 5.4 Idempotency:scan #N references shows exactly 1 entry per child, re-PATCH would no-op ✓
• 5.5 Cross-repo refuse:404 detection on gh issue view proves gate logic ✓

See #21 closing summary for full apply audit trail.