feat(ludic.base): the vocabulary mechanic packages share - Tick, phases, Queue<T>, rng streams, the save tree, the system runner

A mechanic package depends on ludic.base and nothing else: ports (records of
function values for now) for questions, queues for facts, verbs for changes,
phases for order and its own versioned save section. The runner inits, resets,
saves and loads systems in the order added and ticks them phase by phase; a
missing save section is a reset. Tests for each piece and a worked route
between two toy mechanics live under tests/. The old ludic.core (engine ECS
components) is used by examples/library and stays.

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

packages/ludic.base/tests/toys/fishing/index.ludic

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+# a toy mechanic: casting a line. It uses ludic.base and nothing else.
+module toy_fishing
+numbers float
+import "ludic.base"
+export property Caught { species: int = 0, weight: float = 0.0 }
+export property FishingWorld { is_water: fn(float, float) -> bool = null }  # its port
+var world: FishingWorld = null
+var dice: Rng = null
+var casts: int = 0
+export var caught: Queue<Caught> = null                                   # its facts
+export function fishing_bind(w: FishingWorld) -> void { world = w }
+export function fishing_cast(x: float, z: float) -> bool {                 # its verb
+  if not world.is_water(x, z) { return false }
+  casts += 1
+  return true
+}
+function fishing_reset() -> void {
+  casts = 0
+  dice = rng_new(7)
+  caught = q_new("fishing.caught")
+}
+function fishing_tick(t: Tick) -> void {
+  while casts > 0 {
+    let c = new Caught
+    c.species = rng_between(dice, 0, 2)
+    c.weight = 0.5 + rng_float(dice)
+    q_push(caught, c)
+    casts -= 1
+  }
+}
+export function fishing_system() -> System {
+  let s = system_new("fishing", PH_SIMULATE)
+  s.reset = fn fishing_reset
+  s.tick = fn fishing_tick
+  return s
+}