Wolves with a den, fishing, and a mixed diet

Wolves
- Den: a boulder cave at the foot of the rim, sited from the seed (away
  from the sea and spawn, mouth toward the valley, clearing in front)
- Grace period: no wolves days 1-2; they move in on day 3 and howl; hunting
  from night 4; pack of 2, 3 from day 6, 4 from day 9; replaced by day
- Wary pack hunters: circle and dart in one at a time; a lit campfire is a
  safe zone, a torch makes them hesitate, walls block bites (line of
  sight); hit one and the pack turns; hurt wolves flee; a lone wolf is
  timid; by day they defend the den; home at dawn
- Glowing eyes, synthesised howls, can't sleep with wolves prowling
- Wolf pelt and Wolf Cloak (+25 warmth)
- Animals take a committed detour around obstacles

Fishing
- Fishing rod (workbench); cast a float onto the lake, 1.5 s to land a bite
- Perch and rarer trout; faster bites at dawn/dusk and in rain; grill them
- Visible fish near the shore that jump with splash rings

Mixed diet
- Foods belong to meat, fish or greens; each level runs down over ~1.5 days
- One group low: no healing; two low: Malnourished (health drains);
  all three good: Balanced diet (heal x1.5); HUD diet bars; saved

Tests: test_wolves and test_fishing_diet; run_all.sh covers 9 suites

docs/SETUP_ON_NEW_MACHINE.md

@@ -20,6 +20,10 @@ tests/run_all.sh
 ```
 Or one at a time:
 ```bash
+# Wolves: den, grace period, hunting, fire and walls, pack tactics
+godot --headless --path . --script res://tests/test_wolves.gd
+# Fishing and the mixed diet
+godot --headless --path . --script res://tests/test_fishing_diet.gd
 # Wildlife, melee, spear, bow, butchering, cooking + buffs, cloak, drops
 godot --headless --path . --script res://tests/test_creatures_combat.gd
 # Weather, shelter, snap building, support, doors, beds, regrowth