feat: roomier BO2 companion with +/- rank stepping

- Scale the COD page to the screen: larger gun art, text and progress
  ribbon, sized from one viewport unit so it fills a MacBook Pro 16"
  and big monitors and still fits 1280x720 without scrolling.
- Five columns on wide screens and four below, picked by CSS, so the
  server-rendered page already has the final layout.
- Replace the tabs/filters/overview rows with one toolbar of matching
  controls.
- Player and weapon ranks step with + and -: level 55 + 1 is the next
  prestige at level 1, up to max prestige. Presses show at once, batch
  while a save is running, and stepRank does the arithmetic in SQL.
- Clicking a rank still opens exact entry for big jumps.

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

src/lib/game-tracker/rank-progress.test.ts

@@ -6,6 +6,7 @@ import {
 	gameRanksProgress,
 	hasReachedMaxLevel,
 	rankProgress,
+	stepRank,
 	weaponFinished,
 	weaponLevelsProgress
 } from './rank-progress';
@@ -72,6 +73,24 @@ describe('BO2 rank progression', () => {
 		expect(weaponFinished(rules, m27, { level: 16, prestige: 2 }, () => true)).toBe(false);
 		expect(weaponFinished(rules, m27, { level: 17, prestige: 2 }, () => true)).toBe(true);
 	});
+	it('steps level and prestige as one counter', () => {
+		const player = playerRankLimits(rules);
+		expect(stepRank(player, null, 1)).toEqual({ level: 2, prestige: 0 });
+		expect(stepRank(player, null, -1)).toEqual({ level: 1, prestige: 0 });
+		expect(stepRank(player, { level: 55, prestige: 0 }, 1)).toEqual({ level: 1, prestige: 1 });
+		expect(stepRank(player, { level: 1, prestige: 1 }, -1)).toEqual({ level: 55, prestige: 0 });
+		expect(stepRank(player, { level: 54, prestige: 10 }, 1)).toEqual({ level: 55, prestige: 10 });
+		expect(stepRank(player, { level: 55, prestige: 10 }, 1)).toEqual({ level: 55, prestige: 10 });
+		const m27Limits = weaponRankLimits(rules, m27);
+		expect(stepRank(m27Limits, { level: 17, prestige: 1 }, 1)).toEqual({ level: 1, prestige: 2 });
+		expect(stepRank(m27Limits, { level: 16, prestige: 0 }, 3)).toEqual({ level: 2, prestige: 1 });
+		// Historic out-of-range prestiges count as max prestige instead of growing further.
+		expect(stepRank(m27Limits, { level: 1, prestige: 4 }, -1)).toEqual({ level: 17, prestige: 1 });
+		expect(stepRank(m27Limits, { level: 1, prestige: 4 }, 1)).toEqual({ level: 2, prestige: 2 });
+		const uncapped = weaponRankLimits({ ...rules, rankCaps: undefined }, m27);
+		expect(stepRank(uncapped, { level: 40, prestige: 3 }, 1)).toEqual({ level: 41, prestige: 3 });
+		expect(stepRank(uncapped, { level: 1, prestige: 3 }, -1)).toEqual({ level: 1, prestige: 3 });
+	});
 	it('bounds historic out-of-range values without mutating saved data', () => {
 		const rank = { level: 100, prestige: 999 };
 		expect(rankProgress(weaponRankLimits(rules, m27), rank)).toEqual({ value: 51, total: 51 });