Enhance PSK Reporter spots with default-on setting and map-side band/mode/time filters

[Copilot]

This updates the in-progress PSK Reporter feature so users can actually work their own spots in-app: reporting/overlay is enabled by default, and map spots can be filtered by band, mode, and time window (similar to PSK Reporter UX).

• Default behavior and settings integration

  • Set PSK Reporter overlay to default on for new installs.
  • Added a persistent Settings toggle (PSK Reporter Spots) wired to pskOverlayEnabled.

• Map filtering controls (Band / Mode / Time)

  • Added lightweight filter pills on Map when PSK overlay is enabled:
    • Band: ALL | CUR
    • Mode: ALL | FT8 | FT4
    • Time: 15m | 1h | 6h | 24h
  • Applied filtering on returned spots by:
    • current rig band (CUR),
    • selected mode,
    • report age (flowStartSeconds).

• PSK Reporter client query flexibility

  • Extended fetchSpotsForMe to accept optional modeFilter.
  • Keeps FT8 default behavior, and omits mode param for “ALL” mode queries.

• Targeted test coverage updates

  • Added client tests for mode query behavior (mode=FT4 vs omitted mode).
  • Added map filter tests validating combined band/mode/time filtering logic.

val spots = PskReporterClient.fetchSpotsForMe(
    call = call,
    secondsBack = pskTimeFilter.secondsBack,
    modeFilter = pskModeFilter.apiValue, // null => all modes
)

val filtered = filterPskSpots(
    spots = spots,
    bandFilter = pskBandFilter,
    modeFilter = pskModeFilter,
    currentBandHz = GeneralVariables.band,
    maxAgeSeconds = pskTimeFilter.secondsBack,
    nowEpochSeconds = System.currentTimeMillis() / 1000L,
)