Deduplicate food-bias sort logic in choose_task

[itsmiso-ai]

Problem

choose_task() in scripts/main.gd (line 1446) has two separate food-sorting branches that do virtually the same thing:

# Branch 1: "gather" kind with low-food bias (lines ~1455-1465)
if String(kind) == "gather" and should_bias_to_food_gathering():
    tasks.sort_custom(func(a, b) -> bool:
        var a_is_food := String(a.get("resource", "")) == "food"
        var b_is_food := String(b.get("resource", "")) == "food"
        if a_is_food and not b_is_food: return true
        if not a_is_food and b_is_food: return false
        return task_distance(worker, a) < task_distance(worker, b)
    )

# Branch 2: "gather_food" kind (lines ~1467-1477)
elif String(kind) == "gather_food":
    tasks.sort_custom(func(a, b) -> bool:
        var a_is_food := ColonyStance.is_food_gather_task(a)
        var b_is_food := ColonyStance.is_food_gather_task(b)
        if a_is_food and not b_is_food: return true
        if not a_is_food and b_is_food: return false
        return task_distance(worker, a) < task_distance(worker, b)
    )

Both sort food tasks first, then by distance. Branch 1 checks resource == "food" directly. Branch 2 uses ColonyStance.is_food_gather_task() which does the same check via the stance module. The duplication means a change to food prioritization logic must be applied in two places.

Fix

Unify into a single sort comparator. Either:

• Extract a sort_tasks_by_food_priority(tasks, worker) helper that both branches call
• Or collapse gather and gather_food into one kind that always checks ColonyStance.is_food_gather_task(), eliminating the need for separate branches

The second option is cleaner — tasks_for_kind() already maps both "gather" and "gather_food" to gather_gather_tasks() (line 1497), so the separate kinds only exist for the sort comparator.

Acceptance criteria

• Single food-prioritization sort path, not two
• Food gathering still prioritized when should_bias_to_food_gathering() returns true
• Food stance (gather_food priority) still works
• tests/test_colony_stance.gd passes
• Worker behavior unchanged in manual testing