Add match structure (countdown, timer, scoreboard, banner, persistent stats) and capital-ship fleet polish

Match phases (autoload/match_manager.gd, world/game_modes/):
- New server-authoritative MatchManager loops PRE_MATCH (30s countdown,
  ships held invisible/uncollidable, flagships creep into formation) ->
  IN_PROGRESS (active GameMode's clock runs) -> POST_MATCH (winner
  banner, result reported to matchmaking-api) -> back to a fresh
  PRE_MATCH forever, matching the always-on server-pool model instead
  of kicking players to the menu at match end.
- Win-condition logic lives in a new GameMode abstraction (game_mode.gd
  base + team_deathmatch_mode.gd, the only mode so far) so a future
  mode is a new subclass plus one factory branch, no timer/scoreboard/
  banner code changes needed.
- Three new HUD pieces: match_timer.gd (countdown/clock), scoreboard.gd
  (hold-Tab two-team panel), match_banner.gd (winner banner).
- New MatchStats autoload tracks per-match kills/deaths by peer_id
  (including bots), hooked into kill_feed_manager's existing
  report_kill() call site.

Persistent stats (matchmaking-api/):
- Player gains kills/deaths/hours_played columns; new
  POST /matches/report endpoint (server-only, called once at
  POST_MATCH) upserts each real player's totals by callsign via a
  shared app/crud.py helper also used by the matchmaking-queue join
  path. GET /stats/{callsign} returns the new fields alongside mmr/
  wins/losses.

Capital-ship fleet polish (world/flagship.gd, world/world.gd,
ships/ship_movement.gd, autoload/game_config.gd):
- Flagship formations are now a clean vertical line (no per-ship
  position/rotation jitter) so play_creep_in()'s rigid-group tween
  reads as one disciplined fleet arriving together, rising from
  directly below (not a random compass direction) over the full 30s
  countdown.
- Fixed a real bug where the creep-in tween only ever played on the
  server -- MatchManager._run_pre_match() called straight into World,
  server-only code a remote client's own process never runs, leaving
  their flagships static all match. World now triggers it off
  MatchManager.phase_changed instead, which fires identically on every
  peer.
- Fixed a second bug (only reachable on a fresh server boot's very
  first spawn): a phase==PRE_MATCH check that's true even before the
  match loop has genuinely started that phase for the first time fired
  play_creep_in() with a bogus zero-duration tween, corrupting the
  target the real 30s tween read moments later -- flagships would
  settle 4000 units off from their intended formation slot and fire
  from there instead. Guarded on get_remaining_seconds() > 0 too.
- The held ship's camera now actively tracks its own team's flagship
  centroid every tick during the countdown (position_smoothing
  disabled for the hold, since it fights a manually-driven target and
  was the reason the fleet read as invisible) instead of sitting fixed
  and wide-angle; local offset/zoom/smoothing are explicitly reset on
  release so control handback doesn't inherit a stale camera transform.
- _apply_pre_match_hold()/_apply_respawn() now set _dead/
  _held_for_pre_match inside the RPC itself, not just in the
  server-only caller -- those flags never reached remote clients
  before, so WASD wasn't actually blocked for them during the hold.
- Ships now launch from a narrow point directly beneath their own
  flagship formation instead of a full-circle scatter around the spawn
  marker (which could land a spawn behind/inside a hull). Bumped
  flagship_defense_radius so it still comfortably reaches a player who
  flies a straight line to the enemy side without correcting for that
  new offset.

ISN gets a Stealth Corvette hull mixed into its flagship formation
(assets/images/ships/isn/), banner art renamed off opaque UUID
filenames to isn_banner.jpeg/orc_banner.jpeg.

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

matchmaking-api/app/routers/matches.py

@@ -0,0 +1,59 @@
+from fastapi import APIRouter, Depends
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app import crud
+from app.database import get_db
+from app.models import GameServer, Match, MatchPlayer
+from app.schemas import MatchReportRequest
+
+router = APIRouter(prefix="/matches", tags=["matches"])
+
+
+# Called once by the hosting server's MatchManager (spacewar/autoload/
+# match_manager.gd's _report_match_result()) when a match's POST_MATCH phase
+# begins -- persists this match's final kills/deaths/win-loss into each
+# player's running Player totals (kills, deaths, wins, losses, hours_played),
+# and records a Match/MatchPlayer row if the reporting server is a known,
+# registered GameServer. No auth -- same posture as /servers/register today,
+# not a new gap introduced here (see overview/map1.md's design notes).
+#
+# Independent of any Match row the matchmaking queue may have already created
+# when this match was *formed* (see queue_manager.py's _try_form_match) --
+# this always writes a fresh Match/MatchPlayer pair representing how the
+# match actually ended. A queued match can therefore end up with two Match
+# rows (one "how it was formed", one "how it ended"); acceptable since no
+# existing code reads these tables today and there's no migrations tooling to
+# reconcile the schema around it.
+@router.post("/report")
+async def report_match(req: MatchReportRequest, db: AsyncSession = Depends(get_db)) -> dict:
+    server = (
+        await db.execute(
+            select(GameServer).where(
+                GameServer.ip == req.server_ip,
+                GameServer.port == req.server_port,
+                GameServer.mode == req.mode,
+            )
+        )
+    ).scalars().first()
+
+    match_row = None
+    if server is not None:
+        match_row = Match(mode=req.mode, server_id=server.id)
+        db.add(match_row)
+        await db.flush()
+
+    for result in req.players:
+        player = await crud.get_or_create_player(db, result.callsign)
+        player.kills += result.kills
+        player.deaths += result.deaths
+        player.hours_played += result.seconds_played / 3600.0
+        if result.is_winner:
+            player.wins += 1
+        elif req.winner_team is not None:
+            player.losses += 1
+        if match_row is not None:
+            db.add(MatchPlayer(match_id=match_row.id, player_id=player.id, team=result.team))
+
+    await db.commit()
+    return {"status": "recorded"}