Initial commit: Transcience MVP

Top-down twin-stick bullet-hell, Godot 4.7, server-authoritative dedicated
server with client-side prediction. Clients send input only; the server
resolves every hit for both players and enemies (no PvP).

- SimWorld: whole simulation as plain RefCounted objects (no nodes, no
  physics server), ~0.24ms/tick at peak load -- runs headless for free and
  drives 78 tests in under a second
- BulletPool: struct-of-arrays bullet storage, replicated as spawn/despawn
  events rather than per-tick state
- Emitter framework (Ring/AimedSpread/WallGap/ArcSweep) shared by trash
  enemies and bosses -- a new boss is data in src/content/content.gd, no
  simulation changes
- The Warden of the Fold: stationary 4-phase boss built entirely on that
  format
- Lobby hub with a portal into on-demand dungeon instances; one process
  hosts the hub plus every concurrent dungeon
- Emergency escape: 3s server-owned channel, cancelled by damage
- tools/check.sh, test.sh (GUT), smoke.sh (real server + bot clients over
  ENet), bench.gd; git hooks wired to the same scripts
- docs/ARCHITECTURE.md, NETCODE.md, WORKFLOW.md, ROADMAP.md

addons/gut/one_to_many.gd

@@ -0,0 +1,46 @@
+# ------------------------------------------------------------------------------
+# This datastructure represents a simple one-to-many relationship.  It manages
+# a dictionary of value/array pairs.  It ignores duplicates of both the "one"
+# and the "many".  You can disable ignoring dupliates of the "many" via
+# ignore_many_dupes.  This setting is not retroactive and will only affect
+# new calls to add.
+# ------------------------------------------------------------------------------
+var items = {}
+var ignore_many_dupes = true
+
+# return the size of items or the size of an element in items if "one" was
+# specified.
+func size(one=null):
+	var to_return = 0
+	if(one == null):
+		to_return = items.size()
+	elif(items.has(one)):
+		to_return = items[one].size()
+	return to_return
+
+
+# Add an element to "one" if it does not already exist
+func add(one, many_item):
+	if(items.has(one)):
+		if(!ignore_many_dupes or !items[one].has(many_item)):
+			items[one].append(many_item)
+	else:
+		items[one] = [many_item]
+
+
+func clear():
+	items.clear()
+
+
+func has(one, many_item):
+	var to_return = false
+	if(items.has(one)):
+		to_return = items[one].has(many_item)
+	return to_return
+
+
+func to_s():
+	var to_return = ''
+	for key in items:
+		to_return += str(key, ":  ", items[key], "\n")
+	return to_return