release: 1.0.0-beta2

[YueHaxgu]

Summary

• complete the beta2 timeline and canonical layer-mask behavior updates, including selection and editing-context handling
• fix rasterized layer styles applying masks twice by consuming only masks that were actually baked into cels, with undo/redo coverage
• refresh the MoonSprite website, release metadata, changelog, and performance receipt for 1.0.0-beta2
• update the test suite for the canonical mask model and authorized LayersPanel behavior changes

Verification

• pnpm check:release: passed
• Vitest: 86 files, 827 tests passed
• Web production build: passed
• Rust formatting/checks and thumbnail-provider release build: passed
• Performance audit 2026-09-04_22-18-44-643_e2a4e56c: receipt approved

Package hashes

• Setup (10,331,148 bytes): B597964FEAC2E17AA70ED887F9D811E271AAA97465D16D5368DF9240510031E9
• Portable (20,100,608 bytes): 3A9EFEBF72723855F8597574D9523A66A5AAD33BB54653F68C2907CF61308C70

Package binaries are intentionally not committed or uploaded by this PR.