feat(fires): caption the confidence switch and name the slider "Fire intensity (FRP)"

The switch had no visible word saying what ALL / NOMINAL+ / HIGH refer to,
and "Min FRP" assumed the reader knows the acronym. The segmented row
descriptor gains an optional visible `label` (a caption above the group);
the fires row uses "Confidence" and "Fire intensity (FRP)", and the slider
value reads "≥ N MW" so the threshold is still clear. Locales updated.

Co-Authored-By: Claude Fable 5.1 <[email protected]>

src/i18n/same-as-english.json

@@ -121,7 +121,7 @@
     "{value} KM",
     "{value} KM/H",
     "{value} KM/S",
-    "{value} MW",
+    "≥ {value} MW",
     "ΔE",
     "ΔN",
     "▲ {frp} MW"
@@ -197,7 +197,7 @@
     "{type}  SPD: {speed}  HDG: {heading}",
     "{value} KM",
     "{value} KM/S",
-    "{value} MW",
+    "≥ {value} MW",
     "ΔE",
     "ΔN",
     "▲ {frp} MW"