Rank badges and level equipment; no edge scrolling before the mouse has moved

- Military rank badges instead of level numbers: Lv 2-4 bronze chevrons, Lv 5-7 silver bars,
  Lv 8-9 gold stars, Lv 10 gold star in a wreath; rank names in the unit info (EN/DE)
- Equipment grows with the level: shoulder pieces (bronze/silver/gold), helmets with horns
  (creatures) or plumes (heroes), capes from Lv 7, glowing ring from Lv 9, aura at Lv 10
- Fix: before the first mouse move the pointer counts as (0, 0) and the edge scrolling
  moved the camera at the start and after loading a savegame

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

lang/en.lang

@@ -505,3 +505,16 @@ camp.m20.story = Grand Master Valerian Brightshield waits in his citadel beyond
 camp.epilogue = The last shard sinks into the core, and the darkness breathes again. Somewhere above, the Order of the Lightwatch is writing a very long report. | Crookfinger has made tea. You are whole, master. The underworld is yours.
 lair.arrivals = {0} free beds: new creatures arrive at {1}% speed
 job.help = Helping
+
+# ranks (levels 1-10)
+info.rank = Rank: {0}
+rank.1 = Recruit
+rank.2 = Private
+rank.3 = Lance Corporal
+rank.4 = Corporal
+rank.5 = Sergeant
+rank.6 = Staff Sergeant
+rank.7 = Master Sergeant
+rank.8 = Captain
+rank.9 = Colonel
+rank.10 = Warlord