[upstream #16875] Theme cache pin: generated fixtures should cover schema version, precedence, mode absence, property order, shadow canonicalization #298

The resolver output pin in client/src/Providers/__tests__/themeCache.spec.ts (LibreChat-AI#16875) generates one fixture per role and scope. Its generated fixtures should also cover:

• the current schema version, taken from THEME_VERSION instead of a literal 1 (🧬 test: Pin Built-In Theme Output to the Cache Epoch LibreChat-AI/LibreChat#16875 (comment))
• mode-over-theme brand precedence in a single fixture, which also covers the combined case in [upstream #16875] Pin combined brand override precedence in the cache output #297 (🧬 test: Pin Built-In Theme Output to the Cache Epoch LibreChat-AI/LibreChat#16875 (comment))
• multi-source fallback precedence between color roles (🧬 test: Pin Built-In Theme Output to the Cache Epoch LibreChat-AI/LibreChat#16875 (comment))
• canonical order of the persisted properties array before hashing (🧬 test: Pin Built-In Theme Output to the Cache Epoch LibreChat-AI/LibreChat#16875 (comment))
• themes whose mode definition is absent (🧬 test: Pin Built-In Theme Output to the Cache Epoch LibreChat-AI/LibreChat#16875 (comment))
• the composable-shadow canonicalization for the shadow appearance roles (🧬 test: Pin Built-In Theme Output to the Cache Epoch LibreChat-AI/LibreChat#16875 (comment))

None of these is a defect of the cache; they widen what the pin can detect.