# Dead-Code Review

## Summary
Kochwas codebase is remarkably clean with minimal dead code. Primary finding: **yauzl dependency is unused** (reserved for future backup-restore feature). All exports are active, files are properly structured, and no unreachable code paths detected.

## HIGH confidence findings

### Unused Dependencies
- **package.json: yauzl, @types/yauzl** — Declared in `dependencies` but never imported in source code. Added in commit for future backup ZIP import feature (currently only export via archiver is implemented). See `docs/superpowers/session-handoff-2026-04-17.md` which notes: "Import aus ZIP ist noch manueller DB-Copy. yauzl ist bereits als Dependency da, Phase 5b kann das in 10 Minuten nachziehen."

### Exported Types Not Imported Elsewhere
- **src/lib/sw/cache-strategy.ts:3** — `RequestShape` — Exported type only used within the same file as a function parameter. Not imported anywhere (type is passed inline at call site in service-worker.ts). Candidates for internal-only marking.
- **src/lib/sw/diff-manifest.ts:4** — `ManifestDiff` — Exported type only used within same file as a return type of `diffManifest()`. Not imported by any other module.

## MEDIUM confidence findings

None identified. All functions, types, and stores are actively used. All 85 source files are reachable through proper route conventions (+page.svelte, +server.ts, +layout.svelte are auto-routed by SvelteKit).

## LOW confidence / worth double-checking

### Conditional Dead Code in Service Worker (Low risk)
- **src/service-worker.ts:99-110** — The `GET_VERSION` message handler for zombie-SW cleanup is only triggered by `pwaStore` when specific conditions match (bit-identical versions detected after SKIP_WAITING). Works correctly but only fires on edge-case deployments (Chromium race condition). Verified it's needed—comments explain the scenario thoroughly.

### Database Migrations
- **src/lib/server/db/migrations/007-011** — Recent migrations (thumbnail_cache rerun, favicon resets) are cleanup/maintenance operations. Verified they're applied in sequence and read by code (e.g., searxng.ts queries thumbnail_cache). No orphaned migration tables.

## Non-findings (places I checked and confirmed alive)

- **All client stores** (confirm, install-prompt, network, profile, pwa, search-filter, sync-status, toast, wishlist) — Every export used in components
- **All server repositories** (domains, profiles, recipes, wishlist) — All functions imported by API routes
- **All parsers** (ingredient, iso8601-duration, json-ld-recipe) — Used by recipe importer and web search
- **All API routes** — All 27 route handlers are reachable and handler import the functions they need
- **All Svelte components** — No orphaned .svelte files; all imported by routes or other components
- **Static assets** (/manifest.webmanifest, /icon.svg, /icon-192.png, /icon-512.png) — Referenced in app.html, cache-strategy.ts, and manifest
- **Service worker** — All functions in service-worker.ts are called; no dead branches
- **Commented code** — Only legitimate documentation comments (German docs explaining design decisions); no large disabled code blocks

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**Review Scope:** src/ (~85 files), package.json dependencies, tests/
**Tools used:** Grep (regex + pattern matching), Read (file inspection), Bash (git log)
**Confidence Threshold:** HIGH = 100% sure, MEDIUM = 95%+, LOW = contextual