DevQuest v1.2.1 — Production Rack PNG Fix

Patch release for DevQuest v1.2.

Fixes:

• Production-safe PNG rendering for complex rack cards
• Each card is rasterized independently before final row/stack composition
• Signal Orbit, avatar cards and other nested SVG templates now export reliably inside rack PNGs

Validation:

• Production Next.js build passed
• TypeScript and ESLint passed
• 433 tests passed
• Local production smoke passed for a complex two-card rack and a six-card rack

This release preserves the v1.2.0 history and adds a normal patch commit on top.