feat: binary HID-RPC wheel dispatch

[mcuelenaere]

Summary

Wires the TypeWheelReport (0x04) binary HID-RPC opcode into firmware dispatch and updates the browser frontend to use it when the HID-RPC channel is ready. The opcode and queue routing already existed in internal/hidrpc/hidrpc.go, but handleHidRPCMessage had no case for it, so binary wheel frames hit the default arm and were silently dropped. Wheel input had to take the JSON-RPC slow path.

Now wheel rides hidrpc-unreliable-ordered like mouse motion: per-event JSON encode/parse is gone, latency drops on the ARM, and the binary path matches the existing mouse/keyboard pattern. Wire format is [0x04][deltaY: int8][deltaX: int8] — both axes carried.

Two commits:

• feat(hidrpc): dispatch binary TypeWheelReport (0x04) frames — length-strict WheelReport decoder, dispatch case in handleHidRPCMessage, 10 table-driven test cases.
• feat(ui): send mouse wheel via binary HID-RPC when available — new WheelReportMessage class, reportWheelEvent hook, getMouseWheelHandler switches to rpcHidReady ? binary : send(\"wheelReport\", ...) matching the rel/abs mouse pattern.

The JSON-RPC wheelReport method is unchanged; old clients and the transient WebRTC/handshake window keep working.

Checklist

• Ran `make test_e2e` locally and passed
• One problem per PR (no unrelated changes)
• Lints pass; CI green (locally: `go test ./internal/hidrpc/...` + `tsc --noEmit` + `oxlint`)
• Tricky parts are commented in code

---

Note

Medium Risk
Changes the end-to-end mouse wheel input path (new binary opcode handling in Go + new frontend message), which could affect scroll behavior/latency if the wire format or channel selection is wrong; fallback to existing JSON-RPC reduces blast radius.

Overview
Enables mouse wheel events to flow over the binary HID-RPC channel by adding TypeWheelReport handling in the Go dispatcher and a strict WheelReport decoder (with new unit tests) in internal/hidrpc/message.go.

Updates the UI to emit wheel input as a new WheelReportMessage over the unreliable-ordered HID-RPC data channel when rpcHidReady, while keeping the existing JSON-RPC wheelReport path as a backward-compatible fallback. Also tightens a macro marshal error message and logs RTC channel errors using e.type.

^{Reviewed by Cursor Bugbot for commit a5f6d70. Bugbot is set up for automated code reviews on this repo. Configure here.}

[adamshiervani]

No need to be backwards compatible nowadays. The Cloud SPA is versioned, and the LAN access always serves a matching Go API and JS SPA.

Please remove the wheelReport code path.

[mcuelenaere]

Addressed in a5f197b — dropped the JSON-RPC fallback in getMouseWheelHandler and removed the wheelReport entry from the JSON-RPC handler map. Binary 0x04 is now the only path; rpcWheelReport stays but is reached only via handleHidRPCMessage.