This folder turns the findings in ../audit.md into implementation-ready plans. Each plan explains the problem, the proposed design, affected code, edge cases, tests, rollout strategy, observability, and acceptance criteria.

These are planning documents only. No application source has been changed.

Recommended order

Order	Priority	Fix	Expected outcome	Depends on
1	P0	Minify frontend bundles	Smaller JavaScript, especially on the watch page	None
2	P0	Compress and cache static responses	Avoid transferring 1.16MB of raw player JavaScript and repeated revalidation	Fix 1 recommended
3	P1	Optimize logo and icon assets	Remove roughly 500KB of oversized first-load images	None
4	P0	Make manual episode changes asynchronous	Remove full-page reloads between episodes	None
5	P0	Cache and prefetch playback sources	Reduce time from player shell to playable video	Fix 4 recommended
6	P1	Improve player loading and recovery states	Make unavoidable waits understandable and accessible	Can ship independently
7	P1	Represent recommendation refresh state	Stop showing a false empty state during background work	None
8	P2	Cache Simulcast discovery	Remove repeated serial provider requests	None
9	P2	Deduplicate canonical episode refreshes	Prevent duplicate provider work on anime details	None
10	P2	Parallelize watch-data assembly	Reduce watch-page server time without changing behavior	Fix 9 recommended
11	P2	Make watchlist updates local-first	Keep existing-anime status changes DB-only	None
12	P2	Reduce Reviews payload	Lower initial HTML size and rendering cost	Fix 2 recommended

Delivery slices

Slice A: low-risk transfer wins

Ship fixes 1-3 together. They do not change product behavior and should be the safest first release. Capture bundle sizes and response headers before and after deployment.

Slice B: playback responsiveness

Ship fix 4 first, then fix 5. Fix 6 can ship with either. Keep ordinary page navigation as a fallback until asynchronous transitions have proven reliable.

Slice C: honest background work

Ship fix 7. It changes recommendation-state semantics, the handler contract, and the rendered UI together.

Slice D: provider and payload cleanup

Ship fixes 8-12 independently. They are smaller optimizations and should not block the P0 work.

Shared performance gates

Do not replace the current server-rendered architecture with a client-side router.
Keep every asynchronous action recoverable through an ordinary URL or retry action.
Bound all caches by item count and TTL.
Never cache user-specific HTML in shared static caches.
Preserve request cancellation through context.Context and AbortController.
Add measurements before optimizing so regressions are visible.
Validate on a throttled connection as well as localhost; localhost hides transfer and network latency.

Suggested release targets

These targets are directional and should be confirmed under representative production conditions:

Home catalog ready: under 1 second at p75.
Search results after debounce: under 500ms at p75.
Watch page shell: under 800ms at p75.
Warm episode change: under 1.5 seconds to playable at p75.
Cold episode start: under 4 seconds to playable at p75, with a useful status shown after 3 seconds.
Versioned static assets: no revalidation during their one-year cache lifetime.
Reviews initial HTML: under 100KB uncompressed.