### Changed
**Frontend: Type System Consolidation** (~1 hour)
Unified scattered TypeScript types from fragmented structure (`types/`, `lib/api/types/`) into single `src/types/` directory following Next.js 15 best practices.
**Migration**:
- Moved backend DTO types: `lib/api/types/*.ts` → `types/api/` (anima, event, memory, common)
- Moved feature types: `types/sandbox.ts` → `types/features/sandbox.ts`
- Updated 13 import statements across API clients, hooks, components
- Deleted old `lib/api/types/` directory
**Benefits**:
- Single import: `import { Anima, Event, Memory } from '@/types'` (was: `@/lib/api/types/anima`)
- Eliminated type duplication (conflicting Event/Memory definitions)
- Clear organization: `api/` (backend DTOs) vs `features/` (UI types)
- Better IDE autocomplete and type discovery
**Verification**:
- ✅ Build successful (13 routes, 2.0s compile)
- ✅ Linter passed (0 errors, 3 pre-existing warnings)
**Files Changed**:
- Created: `types/api/index.ts`, `types/features/sandbox.ts`
- Modified: 13 files (API clients, hooks, components)
- Deleted: `lib/api/types/` (6 files)
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### Added
**Documentation: Frontend Architecture Overview**
Created `docs/frontend-architecture.md` (288 lines) - comprehensive frontend architecture guide for senior engineers and LLM agents.
**Coverage**:
- Tech stack (Next.js 15, React 19, TypeScript, Tailwind 4, Supabase)
- Complete directory structure with annotations
- 5 core architecture patterns (route groups, two-tier API client, custom hooks, auth flow, type system)
- Key features (landing page, anima dashboard, sandbox AI chat)
- Design system (terminal aesthetic, styling approach)
- Development workflow and API integration
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