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/models.py

@@ -2,7 +2,7 @@ import enum
 import uuid
 from datetime import datetime
 
-from sqlalchemy import DateTime, Float, ForeignKey, Integer, String
+from sqlalchemy import BigInteger, DateTime, Float, ForeignKey, Integer, String
 from sqlalchemy import Enum as SAEnum
 from sqlalchemy.orm import Mapped, mapped_column, relationship
 
@@ -38,6 +38,13 @@ class Player(Base):
     kills: Mapped[int] = mapped_column(Integer, default=0)
     deaths: Mapped[int] = mapped_column(Integer, default=0)
     hours_played: Mapped[float] = mapped_column(Float, default=0.0)
+    # In-game currency, see overview/onfoot.md -- named RAM, stored as a
+    # single integer count of kilobytes (the smallest denomination); the
+    # client formats it up into KB/MB/GB/TB (1000 per step, not 1024) for
+    # display. BigInteger since a long-lived player's total is expected to
+    # climb well past 32-bit Integer's ~2.1 billion ceiling (2.1 billion KB
+    # is only ~2.1 TB).
+    ram_kb: Mapped[int] = mapped_column(BigInteger, default=0)
     created_at: Mapped[datetime] = mapped_column(DateTime, default=datetime.utcnow)
 
 
@@ -57,6 +64,16 @@ class GameServer(Base):
     # once that probe answers.
     player_count: Mapped[int] = mapped_column(Integer, default=0)
     max_players: Mapped[int] = mapped_column(Integer, default=50)
+    # The actual in-match GameMode id (e.g. "team_deathmatch") and map
+    # display name (e.g. "Sector Alpha") this server is running -- distinct
+    # from `mode` above, which is only the matchmaking queue mode ("casual").
+    # Plain strings, not a Mode-style enum: the set of GameMode ids lives in
+    # the Godot client (spacewar/world/game_modes/, world.gd's MAPS), which
+    # this API has no reason to duplicate/validate against. Reported by the
+    # hosting server on every register/heartbeat call (see
+    # spacewar/autoload/network_manager.gd's host_server()).
+    game_mode: Mapped[str] = mapped_column(String(64), default="team_deathmatch")
+    map_name: Mapped[str] = mapped_column(String(64), default="Sector Alpha")
 
 
 class Match(Base):