Refactor farm building speed to builder unit action_speeds and enable infinite charges

config/improvements.yaml

@@ -0,0 +1,15 @@
+# Tile improvements configuration
+# All values must be configurable via YAML as per AGENTS.md
+
+farm:
+  id: farm
+  name: "Boerderij"
+  action: "boerderij_bouwen"
+  texture: "images/farm.jpeg"
+  texture_scale: 0.6 # World-space scale: 0.6 spans nicely across adjacent hexes without repeating unnaturally
+  texture_mapping: "world" # "world" = seamless across adjacent hex tiles; "hex" = centered per tile
+  valid_terrains:
+    - grasland
+    - tundra
+  yield_bonus:
+    voedsel: 1000

config/units/builder.yaml

@@ -0,0 +1,15 @@
+id: builder
+name: Builder
+category: bouwen
+domain: land
+health: 100
+movement_speed: 2.0
+cost: 50
+build_charges: -1 # -1 voor oneindig doorwerken
+infinite_charges: true
+icon: images/units/builder.png
+actions:
+  - verplaatsen
+  - boerderij_bouwen
+action_speeds:
+  boerderij_bouwen: 10.0 # Duur in seconden die deze builder unit nodig heeft voor de actie boerderij_bouwen