feat: complete Phase 3 - Domain Modeling & Data Layer

Implements comprehensive type system, runtime validation, API client,
and testing infrastructure for CS2.WTF.

TypeScript Interfaces (src/lib/types/):
- Match.ts: Match, MatchPlayer, MatchListItem types
- Player.ts: Player, PlayerMeta, PlayerProfile types
- RoundStats.ts: Round economy and performance data
- Weapon.ts: Weapon statistics with hit groups (HitGroup, WeaponType enums)
- Message.ts: Chat messages with filtering support
- api.ts: API responses, errors, and APIException class
- Complete type safety with strict null checks

Zod Schemas (src/lib/schemas/):
- Runtime validation for all data models
- Schema parsers with safe/unsafe variants
- Special handling for backend typo (looses → losses)
- Share code validation regex
- CS2-specific validations (rank 0-30000, MR12 rounds)

API Client (src/lib/api/):
- client.ts: Axios-based HTTP client with error handling
  - Request cancellation support (AbortController)
  - Automatic retry logic for transient failures
  - Timeout handling (10s default)
  - Typed APIException errors
- players.ts: Player endpoints (profile, meta, track/untrack, search)
- matches.ts: Match endpoints (parse, details, weapons, rounds, chat, search)
- Zod validation on all API responses

MSW Mock Handlers (src/mocks/):
- fixtures.ts: Comprehensive mock data for testing
- handlers/players.ts: Mock player API endpoints
- handlers/matches.ts: Mock match API endpoints
- browser.ts: Browser MSW worker for development
- server.ts: Node MSW server for Vitest tests
- Realistic responses with delays and pagination
- Safe integer IDs to avoid precision loss

Configuration:
- .env.example: Complete environment variable documentation
- src/vite-env.d.ts: Vite environment type definitions
- All strict TypeScript checks passing (0 errors, 0 warnings)

Features:
- Cancellable requests for search (prevent race conditions)
- Data normalization (backend typo handling)
- Comprehensive error types (NetworkError, Timeout, etc.)
- Share code parsing and validation
- Pagination support for players and matches
- Mock data for offline development and testing

Build Status: ✓ Production build successful
Type Check: ✓ 0 errors, 0 warnings
Lint: ✓ All checks passed
Phase 3 Completion: 100%

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

src/lib/schemas/player.schema.ts

@@ -0,0 +1,88 @@
+import { z } from 'zod';
+import { matchSchema, matchPlayerSchema } from './match.schema';
+
+/**
+ * Zod schemas for Player data models
+ */
+
+/** Player schema */
+export const playerSchema = z.object({
+	id: z.number().positive(),
+	name: z.string().min(1),
+	avatar: z.string().url(),
+	vanity_url: z.string().optional(),
+	vanity_url_real: z.string().optional(),
+	steam_updated: z.string().datetime(),
+	profile_created: z.string().datetime().optional(),
+	wins: z.number().int().nonnegative().optional(),
+	losses: z.number().int().nonnegative().optional(),
+	// Also support backend's typo "looses"
+	looses: z.number().int().nonnegative().optional(),
+	ties: z.number().int().nonnegative().optional(),
+	vac_count: z.number().int().nonnegative().optional(),
+	vac_date: z.string().datetime().nullable().optional(),
+	game_ban_count: z.number().int().nonnegative().optional(),
+	game_ban_date: z.string().datetime().nullable().optional(),
+	oldest_sharecode_seen: z.string().optional(),
+	matches: z
+		.array(
+			matchSchema.extend({
+				stats: matchPlayerSchema
+			})
+		)
+		.optional()
+});
+
+/** Transform player data to normalize "looses" to "losses" */
+export const normalizePlayerData = (data: z.infer<typeof playerSchema>) => {
+	if (data.looses !== undefined && data.losses === undefined) {
+		return { ...data, losses: data.looses };
+	}
+	return data;
+};
+
+/** PlayerMeta schema */
+export const playerMetaSchema = z.object({
+	id: z.number().positive(),
+	name: z.string().min(1),
+	avatar: z.string().url(),
+	recent_matches: z.number().int().nonnegative(),
+	last_match_date: z.string().datetime(),
+	avg_kills: z.number().nonnegative(),
+	avg_deaths: z.number().nonnegative(),
+	avg_kast: z.number().nonnegative(),
+	win_rate: z.number().nonnegative()
+});
+
+/** PlayerProfile schema (extended with calculated stats) */
+export const playerProfileSchema = playerSchema.extend({
+	total_matches: z.number().int().nonnegative(),
+	kd_ratio: z.number().nonnegative(),
+	win_rate: z.number().nonnegative(),
+	avg_headshot_pct: z.number().nonnegative(),
+	avg_kast: z.number().nonnegative(),
+	current_rating: z.number().int().min(0).max(30000).optional(),
+	peak_rating: z.number().int().min(0).max(30000).optional()
+});
+
+/** Parser functions */
+export const parsePlayer = (data: unknown) => {
+	const parsed = playerSchema.parse(data);
+	return normalizePlayerData(parsed);
+};
+
+export const parsePlayerSafe = (data: unknown) => {
+	const result = playerSchema.safeParse(data);
+	if (result.success) {
+		return { ...result, data: normalizePlayerData(result.data) };
+	}
+	return result;
+};
+
+export const parsePlayerMeta = (data: unknown) => playerMetaSchema.parse(data);
+export const parsePlayerProfile = (data: unknown) => playerProfileSchema.parse(data);
+
+/** Infer TypeScript types */
+export type PlayerSchema = z.infer<typeof playerSchema>;
+export type PlayerMetaSchema = z.infer<typeof playerMetaSchema>;
+export type PlayerProfileSchema = z.infer<typeof playerProfileSchema>;