Shkarko CodeWhale 0.8.52

Added
- SiliconFlow China region provider. Added the siliconflow-CN provider variant for the China regional endpoint, sharing the existing [providers.siliconflow] credentials and SILICONFLOW_API_KEY slot instead of creating a second credential namespace; the provider picker and registry docs now expose the regional route explicitly (#2588, #2615).
- Multimodal /attach image forwarding. Attached images are now sent as OpenAI-compatible image_url content blocks so multimodal providers can actually see image attachments (#2584, #2587, #2607).
- Sub-agent lifecycle hooks and runtime metadata. Sub-agent spawn/complete hook events, mode-change runtime messages, mode metadata on turns, localized context-inspector strings, and drag-to-resize sidebar width are included in this release slice.
Fixed
- Sub-agents now auto-cancel after stale heartbeats. Running sub-agents track manager-visible progress and are auto-cancelled after the configurable [subagents] heartbeat_timeout_secs window (default 300s), releasing their concurrency slot and unblocking parent turns that would otherwise wait forever (#2603, #2614, #2620).
- Work panel state survives transient lock misses. The sidebar caches the last successful Work summary so checklist and strategy progress no longer disappear into "Work state updating..." while the engine briefly owns the shared todo/plan locks (#2606, #2616).
- SiliconFlow-CN no longer breaks main. Filled the missing CLI provider exhaustiveness arms and removed the duplicate/unreachable TUI config arms left by the #2615 landing; direct auth now stores the China-region variant in the shared SiliconFlow provider table (#2616, #2618, #2619).
- v0.8.51 image-attach closure corrected. The /attach multimodal fix landed after the v0.8.51 tag, so this release is the first version that actually contains it for users installing from the published release line (#2584, #2607).
- Legacy SSE MCP reconnects are retryable again. Closed or reset POST /messages requests on stale legacy SSE sessions now trigger the same reconnect-and-retry path as closed SSE streams, removing a release-gate flake and matching the intended recovery behavior (#2597).
- Cache-hit cost accounting uses one telemetry source. Mixed DeepSeek prompt_cache_hit_tokens and OpenAI-style cached_tokens usage payloads no longer infer cache misses from the wrong hit count, avoiding inflated TUI cost estimates on cached DeepSeek turns (#2567, #2609).
- Cygwin/MSYS2 config paths honor exported $HOME. CodeWhale and legacy DeepSeek config roots now prefer a non-empty $HOME before falling back to the platform home resolver, while CODEWHALE_HOME remains the strongest explicit override (#2369, #2610).
Community
Thanks to @xyuai (#2587), @IcedOranges (#2584), @BH8GCJ (#2588), @shenjackyuanjie (#2618, #2619), @idling11 (#2606, #2616), @AresNing (#2578), @caiyilian (#2567), @buko (#2369), @gordonlu, @encyc, and @simuusang (#2603, #2620) for reports, patches, retesting, and release-stabilization signals that shaped this pass.