feat(roaming): faithful QTH定位器 port, live-update toggle, night-mode safe

Rework the Roaming page after user review. It is now a faithful port of the QTH定位器 location panel, not a loose re-skin:

UI (matching the reference layout):
- GPS status dot (real: green when a fresh fix exists, outline when stale/missing) + date + time header
- Lat/Lon rows with DMS and 5-decimal display, big 8-char locator centered below
- 3x3 grid of neighboring 4-char squares with the reference proportions: center column ~2.6x wider (21.4% : 56.2% : 21.4%) and center row the tallest (31.5% : 35.9% : 31.7%); red position marker now placed at the fractional position of the fix inside the center cell (was fixed center)
- No oversized GPS button: live updating is now a Settings toggle '漫游位置实时更新' (stateOfRoamingLive, default on) that drives periodic location refresh

Style & night-mode safety:
- All colors come from MaterialTheme.colorScheme (surfaceVariant/secondaryContainer/error) — no hardcoded cyan/blue from the original app. The red night filter (ColorMatrix keeping only the R channel) blanked the old hardcoded palette; theme colors survive it.
- Chinese nav label '漫游' added to values-zh (was missing, showing English 'Roaming')

Settings:
- OtherSettings.stateOfRoamingLive persisted (default true), toggle row in Other card, height adjusted

Verified: feature:roaming, feature:settings, app compile clean.

core/data/src/main/java/com/rtbishop/look4sat/core/data/repository/SettingsRepo.kt

@@ -76,6 +76,7 @@ class SettingsRepo(
     private val keyStateOfUtc = "stateOfUtc"
     private val keyStateOfLightTheme = "stateOfLightTheme"
     private val keyStateOfNightMode = "stateOfNightMode"
+    private val keyStateOfRoamingLive = "stateOfRoamingLive"
     private val keyStationAltitude = "stationAltitude"
     private val keyStationLatitude = "stationLatitude"
     private val keyStationLongitude = "stationLongitude"
@@ -351,6 +352,7 @@ class SettingsRepo(
                 putBoolean(keyStateOfUtc, new.stateOfUtc)
                 putBoolean(keyStateOfLightTheme, new.stateOfLightTheme)
                 putBoolean(keyStateOfNightMode, new.stateOfNightMode)
+                putBoolean(keyStateOfRoamingLive, new.stateOfRoamingLive)
                 putBoolean(keyShouldSeeWarning, new.shouldSeeWarning)
                 putBoolean(keyShouldSeeWhatsNew, new.shouldSeeWhatsNew)
                 putString(keySstvMode, new.sstvMode)
@@ -368,6 +370,7 @@ class SettingsRepo(
         stateOfUtc = preferences.getBoolean(keyStateOfUtc, false),
         stateOfLightTheme = preferences.getBoolean(keyStateOfLightTheme, false),
         stateOfNightMode = preferences.getBoolean(keyStateOfNightMode, false),
+        stateOfRoamingLive = preferences.getBoolean(keyStateOfRoamingLive, true),
         shouldSeeWarning = preferences.getBoolean(keyShouldSeeWarning, true),
         shouldSeeWhatsNew = preferences.getBoolean(keyShouldSeeWhatsNew, true),
         sstvMode = preferences.getString(keySstvMode, null) ?: "Auto",