Address code review feedback: remove unused imports, fix validation, add missing factory spawn

[Copilot]

Code cleanup and consistency fixes from PR review feedback.

Changes

• Removed unused imports: VectorAbstract, ObjectEntity (multiple files), tps, bossSpawningInterval
• Fixed comment typo: barrel"s → barrel's
• Replaced isNaN with !isFinite: Commands.ts now properly rejects Infinity values in addition to NaN, removed redundant MAX_SAFE_INTEGER checks
• Added factory spawning to Domination: Missing attemptFactorySpawn() call added for consistency with Team2/Team4/Tag/Mothership gamemodes

// Before: players always spawned at team base
public spawnPlayer(tank: TankBody, client: Client) {
    const team = this.decideTeam(client);
    TeamEntity.setTeam(team, tank);
    const teamBase = team.base;
    // ...
}

// After: attempt factory spawn first
public spawnPlayer(tank: TankBody, client: Client) {
    const team = this.decideTeam(client);
    TeamEntity.setTeam(team, tank);
    
    const success = this.attemptFactorySpawn(tank);
    if (success) return;
    
    const teamBase = team.base;
    // ...
}

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