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/McClient.cs

@@ -107,6 +107,9 @@ namespace MinecraftClient
 
         // player effects
         private readonly Dictionary<Effects, EffectData> playerEffects = new();
+
+        // player attributes (e.g., block_break_speed, mining_efficiency, submerged_mining_speed)
+        private readonly Dictionary<string, double> playerAttributes = new();
         
         // Sneaking
         public bool IsSneaking { get; set; } = false;
@@ -2591,6 +2594,13 @@ namespace MinecraftClient
                 if (lookAtBlock)
                     UpdateLocation(GetCurrentLocation(), location);
 
+                // Auto-compute dig duration for survival/adventure mode when not explicitly supplied
+                if (duration <= 0 && protocolversion >= Protocol18Handler.MC_1_8_Version
+                    && gamemode is 0 or 2) // Survival or Adventure
+                {
+                    duration = ComputeAutoDigDuration(location);
+                }
+
                 // Send dig start and dig end, will need to wait for server response to know dig result
                 // See https://wiki.vg/How_to_Write_a_Client#Digging for more details
                 bool result = handler.SendPlayerDigging(0, location, blockFace, sequenceId++)
@@ -2608,6 +2618,52 @@ namespace MinecraftClient
             }
         }
 
+        /// <summary>
+        /// Compute the automatic dig duration in seconds for a block, based on held tool,
+        /// enchantments, effects, attributes, and player state.
+        /// Returns 0 for instant-break blocks.
+        /// </summary>
+        private double ComputeAutoDigDuration(Location location)
+        {
+            try
+            {
+                Block block = world.GetBlock(location);
+                Material blockMaterial = block.Type;
+
+                if (blockMaterial == Material.Air)
+                    return 0;
+
+                // Get held item from player inventory
+                Item? heldItem = null;
+                Item? helmetItem = null;
+                if (inventories.TryGetValue(0, out var playerInv))
+                {
+                    int hotbarSlot = 36 + CurrentSlot; // Hotbar slots are 36-44
+                    playerInv.Items.TryGetValue(hotbarSlot, out heldItem);
+                    playerInv.Items.TryGetValue(5, out helmetItem); // Slot 5 = helmet
+                }
+
+                int ticks = MiningCalculator.ComputeDigTicks(
+                    blockMaterial,
+                    heldItem,
+                    helmetItem,
+                    playerEffects,
+                    playerAttributes,
+                    playerPhysics.InWater,
+                    playerPhysics.OnGround,
+                    protocolversion);
+
+                if (ticks <= 0)
+                    return 0;
+
+                return (double)ticks / Settings.ClientTicksPerSecond;
+            }
+            catch
+            {
+                return 0;
+            }
+        }
+
         /// <summary>
         /// Change active slot in the player inventory
         /// </summary>
@@ -3712,6 +3768,9 @@ namespace MinecraftClient
         {
             if (EntityID == playerEntityID)
             {
+                foreach (var kvp in prop)
+                    playerAttributes[kvp.Key] = kvp.Value;
+
                 DispatchBotEvent(bot => bot.OnPlayerProperty(prop));
             }
         }