fix(desktop): wire up tool_progress so live bash output doesn't blank the app

[esengine]

Root cause of the white screen

ToolProgress was appended to the event.Kind enum (to keep earlier Kind values wire-stable) but never added to the desktop wire map or the frontend. So when bash streams live output mid-turn:

1. kindNames[event.ToolProgress] misses → Go returns the zero value "".
2. toWire emits kind: "".
3. The frontend applyEvent has no case for it and no default → returns undefined.
4. reducer returns undefined → the whole useReducer state becomes undefined.
5. Next render: todoItem reads state.items off undefined → TypeError: Cannot read properties of undefined (reading 'items') → tree unmounts → white screen.

Caught via the new crash overlay (#2691); the [react] stack pointed straight at the todoItem memo. This is independent of the cmd-window popup (#2686) — both just happen while bash runs, which is why hiding the popup didn't stop the blanking.

Fix

• Map ToolProgress → "tool_progress" in kindNames + toWire, add it to EventKind, and handle it in applyEvent (append the chunk to the tool's output, so live progress now actually renders).
• Add default: return s to both applyEvent and the reducer — an event kind a newer kernel emits but this build doesn't name yet is now ignored, never fatal.
• Tighten TestKindNamesComplete to walk every Kind through ToolProgress (the old hand-listed set had missed ToolProgress too, so it stayed green), plus a toWire(ToolProgress) test.

Validation

• gofmt / go vet / go build / go test ./... in desktop/ — pass (the tightened completeness test now fails if any Kind is unmapped)
• npm run typecheck + npm run build in desktop/frontend