Add named Marks and cross-room NPC pathfinding

- Mark: a debug non-collidable named destination (pixel-art target icon),
  editor tool + name modal, globally-unique names, programmatic Room:addMark
- NPCs walk to Marks: each RGB copy is a per-room resident (like the player),
  running its own A* on its own colour layer, transferring rooms as it crosses
  seams; rendered and collided by the room it currently stands in
- Player copies are obstacles in NPC pathfinding
- A* is footprint-aware for multi-cell NPCs
- Editor: click an NPC to open a filterable destination picker
- Ink: Dialogue.open binds walk_to; Jorge can be sent to "end"/"begin"
- Fix: a blocked NPC now replans each tick and resumes instead of freezing
- [npc] move diagnostics under DEBUG (start/goal/route or block reason)
- Docs (adding-npcs) + CLAUDE.md LÖVE 11.x/float-colour corrections
- Fix test harness loadSprite stub; movement tests green (28)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

main.lua

@@ -100,6 +100,7 @@ function love.update(dt)
 		if repeatedMove and not Dialogue.isOpen() and not MapManager:isOpen() then gameWorld:movePlayer(currentRoom, repeatedMove) end
 	end
 	currentRoom:update(dt)
+	if gameWorld then gameWorld:update(dt) end
 	MapManager:record(currentRoom)
 
 	-- if love.keyboard.isDown("w") then worldSha = worldSha + 1 end
@@ -174,6 +175,8 @@ function love.draw()
 	love.graphics.setColor(1, 1, 1, 1)
 	if DEBUG then love.graphics.draw(sideBarCanvas, sideBarBox.x, sideBarBox.y) end
 	if DEBUG then editorDrawNoteHover() end
+	if DEBUG then editorDrawMarkPicker() end
+	if DEBUG then editorDrawMarkNameEditor() end
 	love.graphics.print("Current FPS: "..tostring(love.timer.getFPS( )), 10, 10)
 	PerfProfiler:draw()
 	Dialogue.draw()
@@ -229,6 +232,24 @@ function love.keypressed(key)
 		return
 	end
 
+	-- The mark modals (destination picker, name entry) own the keyboard while open:
+	-- characters filter/type via love.textinput, Enter confirms, Esc cancels.
+	if DEBUG and (markPickerActive() or markNameEditorActive()) then
+		if key == "escape" then
+			editorCancelResponse()
+		elseif key == "return" then
+			response = ""
+			editorCompleteResponse()
+		elseif key == "backspace" then
+			local byteoffset = utf8.offset(response, -1)
+			if byteoffset then
+				response = string.sub(response, 1, byteoffset - 1)
+				editorTextHandler(response)
+			end
+		end
+		return
+	end
+
 	-- Tab toggles the editor's note overlay (DEBUG-only; default on).
 	if DEBUG and key == "tab" then
 		NOTES_VISIBLE = not NOTES_VISIBLE