feat: comprehensive streaming improvements
Runtime _connectStream improvements:
- Connection status as reactive signals: _connected, _latency, _frames, _reconnects
injected on stream proxy so UIs can show connection health
- Fixed RLE decoder: 2-byte LE count (was 1-byte, mismatched relay encoder)
- Schema caching: 0x32 SchemaAnnounce frames now parsed and cached
- RTT tracking: receivers send periodic pings (5s), measure round-trip latency
- Better reconnect logging: includes URL and attempt count
Relay tests (57 total):
- catchup_merges_multiple_diffs: sync + 3 diffs → 1 merged frame
- catchup_diffs_only_no_sync: diffs without sync → merged frame
- catchup_preserves_version_counters: conflict resolution versions kept
New example:
- timer-multi-action.ds: every timer + multi-action buttons verified
Documentation:
- STREAM_COMPOSITION.md: 4 new sections (Diff Batching, Connection Status, RTT, Relay Merging)
- Updated example table with streaming-dashboard.ds and timer-multi-action.ds
All 9 examples pass regression (44-70KB each)
598ecde59c