chore: prepare v0.21.1 release

[Devin-AXIS]

What changed

• Align ipollowork-server and ipollowork-orchestrator with the existing 0.21.1 desktop version.
• Remove a stale Design test for a withdrawn bundled template.
• Update Video Studio test assertions to match the current canvas warning and multi-source rebuild behavior.
• Restore template-market tests to the current curated customer catalog.

Why

The formal release gate requires all package versions to match. Current main also contained stale post-merge test assertions that failed against the already-shipped Design, Video Studio, and curated template behavior.

Impact

No user-facing Design, Video, template, plugin, or Skill behavior changes. This commit only aligns release metadata and test coverage with current behavior.

Verification

• App unit tests: 743 passed
• Server tests: 446 passed, 3 skipped
• App typecheck: passed
• Orchestrator typecheck: passed
• Release review and v0.21.1 tag verification: passed
• Maintainability audit and git diff check: passed