Pawns and pathfinding
Add pathfinding to the pawns so that they can navigate the map. Pawn tasks will be covered in milestone 5; this milestone is specifically about setting up navigation. Some of the AC here will not represent in-game functionality, rather a debug proof-of-behaviour.
Revised after #80. The original plan proved navigation by letting the player select a pawn and right-click a destination. That was always scaffolding — directly instructing pawns to move is not a feature of the finished game — and it turned out to be expensive scaffolding, needing selection, input arbitration and unreachable feedback before a pawn took a step. #81 is closed in favour of #95, a debug-only scatter command that sends every idle pawn to a random reachable tile. It proves more of the real system (Pawns.move_to(), the real frame loop, generated terrain, several pawns at once) and builds nothing that has to be removed later.
The terrace question underneath all of this is settled: tools/probe_pawn_terrace.gd shows a pawn riding the steps rather than cutting through them, climbing and descending, with A* routing over a one-level riser.
AC:
- A debug-only command sends idle pawns walking to reachable destinations, with several moving at once (#95)
- Pawns have a configurable movement speed (#80, done)
- Pawn
stateandcellfollow the walk rather than updating only on arrival, and are visible in the debug panel (#95) - If the debug panel is open, draw the navigation paths of all pawns that are currently moving (#82)
- Each terrain kind (sand, grass, snow etc) will have a different movement cost; navigating should balance terrain costs and time taken to reach the destination (#79)
Out of scope:
- Any player-facing move order. The player will never command a pawn to a tile directly
- Visual feedback for an unreachable destination.
Pawns.move_to()returnsfalseand the empty-path case has unit coverage; a real need for surfacing it is most likely to arrive with #83, and should be designed against that case - Pawn selection is no longer required to prove navigation. It moved to milestone #6 (Selection and inspection) as #78, which now covers pawns and buildings
- Flying pawns that go above ground and ignore terrain costs
- Swimming pawns - water is an impenetrable barrier for now
