GNSS 快照到位置与时钟

sequenceDiagram
participant D as GNSS Runtime
participant L as LocationService
participant T as TimeUpdater
participant UI as Sky Plot
D->>L: revision/fix
L->>L: validate/filter
L-->>UI: fix or explicit no-fix
D->>T: valid RMC epoch only
UI->>D: snapshot
D-->>UI: sats/status/diagnostics