chore(dead-code): remove 26 verified orphan files (~72KB / -2,774 lines)

[Agions]

🐱 Dead Code Cleanup — Phase 1 (conservative, ~72 KB / 26 files)

Summary

Removes 26 verified orphan source files totaling ~72 KB / -2,774 lines identified through:

• ts-prune static export analysis
• Recursive reverse import graph traversal
• Dynamic import('@/...') string-literal sweep (caught 2 false positives)

What's removed

A. 12 back-compat shim files (commented "21+ files import" but verified 0 actual references post v2.x refactor):

• src/components/{index.ts, ui/confirm-dialog.tsx}
• src/context/SettingsContext.tsx
• src/hooks/index.ts
• src/providers/AppProvider.tsx
• src/core/pipeline/step-chain.ts
• src/core/services/{base-ai-service, novel-helpers, scene-analyzer.service, script-analyzer.service, video-composition.types}.ts
• src/core/stores/middlewares/persistWithDebounce.ts (had @deprecated tag)

B. 14 real orphan source files (zero references anywhere in repo):

• src/pages/project-edit/hooks/useProjectEdit.ts (569 lines, Container hook left orphaned after page split refactor)
• src/styles/{design-tokens, motion}.ts (only theme.ts is imported; motion.ts keyframes duplicated in globals.css)
• src/shared/hooks/use-animation-frame.ts (10.5 KB RAF hook library, unused)
• src/shared/components/ui/{accordion, async-boundary, breadcrumb, drawer, form, use-form}.tsx
• src/core/validation/schemas.ts (270-line Zod)
• src/core/domains/novel/services/emotion-detector.service.ts
• src/core/services/video/ffmpeg-wasm/ffmpeg-wasm.types.ts
• src/features/editor/components/timeline.types.ts

Preserved (verified needed)

• src/shared/types/cssmodule.d.ts — ambient *.less/*.css declarations, used by 60+ less imports
• src/components/business/CompositionStudio.tsx + RenderCenter.tsx — used by 3 import() sites in ProjectDetailPage + StepComposition + StepRender

Verification

Check	Result
npm run lint --quiet	✅ 0 errors
npx tsc --noEmit	✅ 0 errors
npm test --runInBand (90 suites)	✅ 1596 pass, 4 skip, 0 fail
npm run build	✅ OK

Diff

 26 files changed, 2774 deletions(-)

Out of scope (Phase 2 candidates, ~443 KB remaining)

• 🅲️ 4 orphan pages/ directories (auto-pipeline/project-detail/project-edit/video-editor, ~256 KB) — needs test import path migration
• 🅳️ packages/common/ half (utils/formatters/motion/hooks/domain/components/validation, ~192 KB) — only constants is used; effectively aborts the monorepo refactor

Lesson learned (patched into this PR's analysis method)

Dynamic import('@/components/business/xxx') string-literal calls are invisible to static import regex sweeps. Initial candidate list had 2 false positives (CompositionStudio + RenderCenter shims); tsc --noEmit caught them immediately after git rm, files were restored via git restore --staged --worktree. Always run tsc --noEmit after the first batch of deletions before committing.