Same top-banner pattern as the stale indicator but with red accent
and 'Connection lost — retrying every 2s...' message. Page gets
subtle greyscale/dim instead of a blocking overlay.
Subtle top banner with dimmed page (not a blocking overlay like the
full disconnect state). Shows elapsed time since last update.
Separate from the hard disconnect which triggers after 3 fetch failures.
Debug panel: added 'Stale' button to test.
- Zero state: bouncing dice + message when no game exists
- Disconnected: greyed overlay after 3 consecutive fetch failures,
with retry countdown
- Game over: gold banner with winner name + confetti animation,
detected from log ('WINS!') or single remaining player
- Debug panel: Ctrl+Shift+D toggles hidden panel with buttons to
test all four states (zero, playing, gameover, disconnected, reset)
- Also fixed player panel to use p.number for current-turn matching
and property ownership display
