Add game mode categories, character creation, on-foot ship/hub mode, RAM currency, and in-ship navigation

Bundles several sessions' worth of previously uncommitted work: map
categories with Domination/Conquest/King of the Hill mode stubs and a
server-list mode filter; a procedurally-drawn character-creation screen
replacing the old callsign-only PROFILE overlay; the on-foot groundwork
(walkable station hub, ship interior, character controller) plus the RAM
currency backend; and today's addition, an in-ship Helldivers-2-style
navigation table that QUICK PLAY's queue/connect flow and the Belters/
Military hub travel now live behind, with hub-and-ship return paths and a
context-aware pause menu usable both in-match and inside the ship.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

matchmaking-api/app/config.py

@@ -15,5 +15,15 @@ class Settings(BaseSettings):
     # to "offline" and back.
     server_stale_seconds: int = 20
 
+    # RAM payout formula for POST /matches/report (see overview/onfoot.md) --
+    # every reported player gets ram_payout_participation_kb just for being
+    # in the match, plus ram_payout_per_kill_kb per kill, plus
+    # ram_payout_win_bonus_kb if they won. Placeholder numbers, not balanced
+    # against anything -- tune freely, nothing else in the schema depends on
+    # the specific values.
+    ram_payout_participation_kb: int = 50
+    ram_payout_per_kill_kb: int = 15
+    ram_payout_win_bonus_kb: int = 200
+
 
 settings = Settings()