feat(cloud): cloud task SSE streaming

[tatoalo]

Problem

ph_code_sse_streaming_cloud_runs.mp4

Cloud task log viewing used polling (500ms when viewing, 60s if in background) which was inefficient, had dedup complexity, and couldn't stream status changes in realtime. Also it was kinda bad.
We also had missing comms when a remote sandbox was torn down before the terminal status event arrived, which resulted in ph-code to nevel learn about the run being completed and always show a broken "in progress" state which was not the reflection of the real one.

Added a ton of tests just to make sure this is robust and covers some edge cases.
Diid a lot of manual testing, would appreciate a couple of eyes testing this as well please 🙏🏻

(PostHog/posthog#53754)

Changes

• Complete rewrite of CloudTaskService from polling to SSE streaming with bootstrap (fetch history + open SSE with start=latest), exponential backoff reconnect, and handleStreamCompletion that checks actual run status on any stream error
• aadded an sse parse to parse strem chunks with support for id, event, and multi-line data fields
• a bit of refactor to extract TaskRunStatus, TERMINAL_STATUSES, and isTerminalStatus() to @shared/types
• rewrote watchCloudTask to pass apiHost/teamId directly, added retryCloudTaskWatch, and handleCloudTaskUpdate now handles SSE error events (moved the auth concern to the renderer which already has the auth state, keeping the main-process service simpler)
• sidebar now reads cloudStatus from session store (updated via SSE) instead of waiting for API task refetch
• status rename "started" → "queued" to match BE API