Speed hack improvements): implement walk and attack speedhack anti-cheat checks

[Rhefew]

This PR introduces real-time anti-cheat checks for player movement (walking) and skill casting (attacks) to identify and prevent speed-hacking.

Walk Speed Checks:

• Keeps a rolling history of the player's recent walks (_recentWalks).
• Computes expected travel times using the player's dynamic client movement speed (factoring in underwater stats, safezone overrides, and speed attributes).
• Automatically flags walks that occur too rapidly or have abnormal start coordinate offsets, warps/rubberbands players back, and records warning violations leading to an account ban if limits are exceeded.

Attack Speed Checks:

• Compares attack/skill cast intervals against the expected timing of the player's current Stats.AttackSpeed attribute.
• Applies checks across normal hits, targeted skills, and area skills.
  Verification & Unit Tests:
• Adds SpeedHackAntiCheatTests.cs covering safezone bypasses, normal/mount speed variations, warp resets, attack speedhack detection, and automatic account bans.

[Rhefew]

Closed to avoid a mess with the tracking history