CatSkinC

Added

• WebSocket client using native java.net.http.WebSocket (Java 11+) for high-performance real-time skin sync.
• Automatic protocol negotiation — client sends x-catskinc-protocol: 3 header on WebSocket handshake.
• Resilient connection management:
  • Exponential backoff reconnection (1.5s → 60s max).
  • Shared circuit breaker across REST, SSE, and WebSocket (unified failure tracking).
  • Automatic fallback to SSE when WebSocket fails or protocol is unsupported.
• Session-token authentication on WebSocket with auto-subscription to local player UUID.
• Protocol version verification in welcome message — closes connection on mismatch.
• In-game toast notifications for WebSocket-originated events (skin updates, server messages).
• Myopia skin LOD for CatSkinC-managed remote skins. When enabled, distant players use lazily cached, pixel-perfect half, quarter, or eighth-resolution copies while GUI, inventory, and tab-list skins retain full resolution.
• A Myopia settings screen with an enabled toggle, a 4–128 block base-distance control, Normal and Panicked modes, and links to Minecraft's keybinding menu.
• Default keybindings for increasing and decreasing the Myopia range with the Up and Down arrow keys. All settings are persisted in catskinc.json.

Changed

• Join flow now attempts WebSocket first, falls back to SSE on failure.
• Shared circuit breaker state between ServerApiClient and WebSocketClient — REST/SSE/WS failures all contribute to the same breaker.
• Heartbeat handling — application-level JSON ping/pong (30s) replaces binary WebSocket ping frames for consistency.

Fixed

• Broadcast framing — WebSocket clients now receive raw JSON (SSE data: prefix stripped server-side).
• Handshake protocol header — added X-CatSkinC-Protocol to WebSocket upgrade request.
• Auth race — session token acquired synchronously before WebSocket connection attempt.
• Protocol defense — client verifies protocol_version in welcome message, closes on mismatch.
• Fallback trigger — SSE fallback now activates on abnormal post-connect disconnections, not just initial connect failure.
• Toast handler — implemented proper Toasts.info() with translatable titles.
• Select-Fetch race eliminated: selectSkin() now chains thenRun(refresh) so the POST completes before the GET, eliminating the 4-8s skin delay after upload.
• Pending selections cache: PENDING_SELECTIONS returns the uploaded skin URL immediately after select, avoiding old-skin flashing.
• LAST_CHECK on success only: failed fetches no longer reset the 5s poll timer, preventing a 15s blackout window.
• Fast-retry after null skin: retries fetch in 2s when the server has no cached skin yet, reducing initial sync from 15s to 2s.
• Poll interval reduced: 15s → 5s for faster periodic sync.
• SSE clear-skin handling: clears BASE_CACHE/TALKING_CACHE on null URL, so players properly revert to the default skin.
• SSE reconnect delay: added 1.5s–60s exponential backoff on stream close (was instant reconnect), preventing server flooding.
• Circuit breaker in SSE: SSE checks circuitOpenUntilMs before connecting, eliminating useless retries during outage.
• AtomicInteger: consecutiveFailures switched to AtomicInteger for correct failure counting.
• Always destroy old textures: removed identity check gate on texture release to prevent GPU memory leaks.
• Fixed HTTP 401 on skin downloads: Added signDownloadUrl() method that appends ?exp=&sig= HMAC-signed query parameters to download URLs using the client's requestSigningKey. This matches the server's verify_download_signature() check when ENFORCE_SIGNED_DOWNLOADS=true.
• Replaced per-player TextureManager registrations with a single shared dynamic texture: CatSkinC no longer registers per-player textures with the vanilla TextureManager. Downloaded NativeImage objects are cached and pixel-copied into one shared catskinc:dynamic/active texture on each render frame. This prevents F3+S debug dumps from saving every player's skin to disk.
• Security: Request signing (HMAC-SHA256) applied to WebSocket upgrade request.
• Hardened transitive dependencies against Dependabot advisories. Added resolutionStrategy { force ... } constraints in build.gradle to pin patched versions of vulnerable transitive libraries on both the project and buildscript classpaths:
  • Netty → 4.1.136.Final (fixes GHSA-558v-64gr-wgg4 Bzip2Decoder infinite loop and related netty advisories).
  • Log4j → 2.25.4 (fixes Log4j TLS hostname verification, XML escaping, and related advisories).
  • Guava → 32.0.0-jre (fixes temp-dir and information-disclosure advisories).
  • Commons IO → 2.16.1, Commons Compress → 1.26.0, Commons Lang3 → 3.18.0.
  • Buildscript classpath: Commons Text → 1.12.0, Commons Beanutils → 1.11.0, Plexus Utils → 3.6.1.
• These libraries are Minecraft-provided runtime/build-tooling dependencies and are not bundled into the shipped mod JAR, so the end-user artifact is unaffected; the constraints keep the dev runtime and CI dependency graph clean.