Refactor DiggingTask and embed it in Tasks enum

- Remove lifetime and path storage from DiggingTask, make it Copy.
- Add a placeholder `new` constructor that accepts a path.
- Update the Tasks enum to hold a DiggingTask value.
- Reorder module declarations and re‑export order for tasks.
- Add a commented‑out tasks field to MinerUnit as a preparation step.

src/app/states/skirmish_states/units/miner.rs

@@ -1,4 +1,4 @@
-use crate::app::states::skirmish_states::{Players, units::Unit};
+use crate::app::states::skirmish_states::{Players, tasks::Tasks, units::Unit};
 
 #[derive(Debug, Clone, Copy, PartialEq)]
 pub struct MinerUnit {
@@ -6,6 +6,7 @@ pub struct MinerUnit {
     hp: u16,
     can_dig: bool,
     digging_power: f32,
+    // tasks: Vec<Tasks>,
 }
 
 impl MinerUnit {
@@ -15,6 +16,7 @@ impl MinerUnit {
             hp: 100,
             can_dig: true,
             digging_power: 0.55,
+            // tasks: Vec::new(),
         }
     }
 }