ludic.physics, ludic.character, ludic.vehicles: fact records reused, and phys_sink allocates nothing

The per-frame sweep over physics, character, vehicles and nav found three fact makers that made a record per fact: contacts and splashes, the character's and the vehicles'. Each keeps a pool now, as wildlife's and npc's do (q_unheld). phys_sink, asked on every removal, built two new lists each time; it filters into a kept spare pair and swaps. ludic.nav's paths and crowds already allocate nothing, and none of the four builds a string per call. What remains at load, reset or a world swap is not per frame. vehicle_feed takes its state mut. vehicles_test: 1000 fed facts, drained turn by turn, use at most 4 records. All packages 421.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

packages/ludic.physics/state.ludic

@@ -46,12 +46,17 @@ export state PhysicsState {
   ph_hard: float = 2.0            # metres a second: a contact under this is not a fact
   ph_floats: []int = new []int         # buoyant bodies' ids
   ph_float_k: []float = new []float      # and theirs: buoyancy, linear drag, angular drag, wet
+  ph_floats2: []int = new []int        # the spare pair phys_sink filters into
+  ph_float_k2: []float = new []float
   ph_rx: float = 0.0               # where the last phys_resolve put a body
   ph_rz: float = 0.0
   ph_walkers: []pointer = new []pointer   # a walker id is its place here; null once removed
   ph_ids: []int = words(PH_CAP * 2)
   ph_vals: []float = floats(PH_CAP * 4)
   ph_facts: Queue<PhysFact> = ph_facts__new()
+  ph_fpool: []PhysFact = new []PhysFact   # every fact record made, reused once no drain holds it
+  ph_ffree: []PhysFact = new []PhysFact
+  ph_fnext: int = 0
 }
 
 # the facts, oldest first