Add automatic mining-speed and dig-duration handling

- Add BlockHardness.cs with hardness data for all 1053 blocks from MC 1.21.11
- Add MiningCalculator.cs with version-aware dig duration computation
  - Tool speed from ToolComponent (1.20.6+) or legacy hardcoded tables
  - Efficiency enchantment (legacy: level^2+1, 1.21.11+: mining_efficiency attribute)
  - Haste/Conduit Power/Mining Fatigue effects
  - BLOCK_BREAK_SPEED attribute (1.20.6+)
  - MINING_EFFICIENCY and SUBMERGED_MINING_SPEED attributes (1.21.11+)
  - Underwater penalty with Aqua Affinity support (legacy) or attribute (modern)
  - Airborne penalty
  - Correct tool for drops check (30 vs 100 divisor)
- Modify McClient.DigBlock to auto-compute duration for survival/adventure mode
- Cache player attributes from OnEntityProperties in McClient
- Expose duration parameter in ChatBot.cs scripting wrapper
- Add /downloads/ to .gitignore

Agent-Logs-Url: https://github.com/MCCTeam/Minecraft-Console-Client/sessions/579df446-a335-4174-9a8b-4d66173c82b1

Co-authored-by: milutinke <441903+milutinke@users.noreply.github.com>

MinecraftClient/Scripting/ChatBot.cs

@@ -1089,9 +1089,10 @@ namespace MinecraftClient.Scripting
         /// <param name="direction">Example: if your player is under a block that is being destroyed, use Down</param>
         /// <param name="swingArms">Also perform the "arm swing" animation</param>
         /// <param name="lookAtBlock">Also look at the block before digging</param>
-        protected bool DigBlock(Location location, Direction direction, bool swingArms = true, bool lookAtBlock = true)
+        /// <param name="duration">Dig duration in seconds. 0 = auto-compute for survival, or instant for creative</param>
+        protected bool DigBlock(Location location, Direction direction, bool swingArms = true, bool lookAtBlock = true, double duration = 0)
         {
-            return Handler.DigBlock(location, direction, swingArms, lookAtBlock);
+            return Handler.DigBlock(location, direction, swingArms, lookAtBlock, duration);
         }
 
         /// <summary>