Top-of-hour time signal (F110.3) misses its 300s drain window ~4×/day on demo

[genwave-radio]

📡 Observed

First full day on v5.0.0 (demo, 08-13→08-14 Loki sweep): a new-to-the-fleet warn family, 4 hits in 24h —

TimeDate deferral armed for 13:00 dropped undrained — 336s past its armed hour (budget 300s); a late time check would invent the hour.
TimeDate deferral armed for 17:00 dropped undrained — 353s past its armed hour (budget 300s); a late time check would invent the hour.
TimeDate deferral armed for 18:00 dropped undrained — 312s past its armed hour (budget 300s); a late time check would invent the hour.
TimeDate deferral armed for 21:00 dropped undrained — 328s past its armed hour (budget 300s); a late time check would invent the hour.

All four overruns are shallow (312–353s vs the 300s budget).

🧭 Context

• F110.3 (join-the-ident time signal, PR fix: time announcements join the station ident (gh-#453) #461): the TimeDate segment arms for the top of the hour and must drain within a 300s budget, else it drops — a later check would announce the wrong hour.
• The drop is by design and fails safe: no air harm, music continues. The cost is a missed time signal — ~4 of 24 hours yesterday.
• Feature has been live on the demo box since the v3.5.0 deploy (08-12); the 08-12/08-13 sweeps saw zero of these. First observed after the v5.0.0 deploy — could be v5 break-cadence changes, or just small-sample luck. One day of data so far.

🤔 Hypothesis

A long track straddling the hour pushes the first eligible break past +300s. All overruns being <1min past budget supports "the break arrives just late", not "the drain is stuck".

🛠️ Options

1. Measure first: keep counting for a few days; if it holds at ~4/day with shallow overruns, tune.
2. Widen the budget modestly (e.g. 300→420s) — a time signal at :06 is still an honest "top of the hour" join? (Design call.)
3. Make arming break-aware: skip arming when the playing track already extends past hour+budget, silencing the warn for unwinnable hours (pure noise reduction, no behavior change).

No action on air behavior needed — filed to track frequency and decide whether the budget deserves tuning.