Add comprehensive documentation for active frontend pattern migrationsdiscovered through analysis of 200+ git commits touching site/ files:Core Migrations:- Emotion → Tailwind CSS (strict 'no new emotion' policy)- MUI Components → Custom/Radix/shadcn (Tooltips, Tables, Buttons)- MUI Icons → lucide-react with specific icon mappings- spyOn → queries parameter for GET endpoint mocks in Storybook- localStorage → user_configs table for user preferencesNew Documentation:- Icon migration mappings (BusinessIcon→Building2Icon, etc.)- Radix component prop naming conventions (placement→side)- cn() utility usage for conditional className merging- Chromatic testing best practices (prefer snapshots over assertions)Includes concrete before/after examples and migration patterns to guidedevelopers away from deprecated approaches toward current best practices.Analysis based on PRs:#20948,#20946,#20938,#20905,#20900,#20869,#20849,#20808,#20530,#20479,#20261,#20201,#20200,#20193,#20318---🤖 This change was written by Claude Sonnet 4.5 Thinking using mux and reviewed by a human 🏂