feat: major dependency upgrades, remove Redis, fix mongoose 9 types

Dependencies upgraded:
- svelte 5.38→5.55, @sveltejs/kit 2.37→2.56, adapter-node 5.3→5.5
- mongoose 8→9, sharp 0.33→0.34, typescript 5→6
- lucide-svelte → @lucide/svelte 1.7 (Svelte 5 native package)
- vite 7→8 with rolldown (build time 33s→14s)
- Removed terser (esbuild/oxc default minifier is 20-100x faster)

Infrastructure:
- Removed Redis/ioredis cache layer — MongoDB handles caching natively
- Deleted src/lib/server/cache.ts and all cache.get/set/invalidate usage
- Removed redis-cli from deploy workflow, Redis env vars from .env.example

Mongoose 9 migration:
- Replaced deprecated `new: true` with `returnDocument: 'after'` (16 files)
- Fixed strict query filter types for ObjectId/paymentId fields
- Fixed season param type (string→number) in recipe API
- Removed unused @ts-expect-error in WorkoutSession model

.gitea/workflows/upload.yml

@@ -33,7 +33,6 @@ jobs:
           git reset --hard origin/master
           pnpm install --frozen-lockfile
           pnpm run build
-          redis-cli KEYS 'recipes:*' | xargs -r redis-cli DEL
           sudo systemctl stop homepage.service
           mkdir -p dist
           rm -rf dist/*