Phase 4: menu descriptors for 16 states

Game-file footprint unchanged: still one line in main.lua.

Adds descriptors for actions_menu, worldmap, alchemy_table, journal, character,
inventory, and a shared one for the full-screen prose states (menu_text,
ingame_message, menu_message). The prose states also push their text into the
console history, so the existing review keys walk the manual paragraph by
paragraph rather than delivering it as one unusable utterance.

Two driver improvements, both prompted by real failures the self-test caught:

- menus.getAnyUpvalue finds a file-local across all of a state's functions and
  one level into inner closures. Safe because a Lua file-local is a single
  shared upvalue. Needed because actions_menu and worldmap build their lists in
  open() and never reference them in keypressed, so the named probe function
  found nothing. The generic probe path now falls back to this.

- menus.hasUpvalue checks that a local exists rather than that it holds a value.
  getUpvalue cannot distinguish 'no such local' from 'declared but currently
  nil', which made the self-test report PROBE BROKEN for worldmap, whose
  'local options' is nil until the screen is first opened.

patches/popups.lua now stands down for any state that has a descriptor.
inventoryCursorPopup.set only fires when an item is under the cursor, so empty
slots and empty tabs were silent and you could not tell the cursor had moved.
The inventory descriptor reports item-or-empty plus slot and tab instead.

21/21 testbed checks, history unit tests passing.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

accessibility/states/inventory.lua

@@ -0,0 +1,61 @@
+-- states/inventory.lua — the item grid.
+--
+-- The inventoryCursorPopup patch already speaks item details, but only when an
+-- item is actually under the cursor. Moving onto an empty slot, or switching to
+-- an empty tab, produced silence -- so you could not tell whether the cursor had
+-- moved, which tab you were on, or that the tab was simply empty.
+--
+-- This descriptor owns narration for this screen instead: it reports the item if
+-- there is one, "empty" if not, and the category whenever the tab changes.
+-- patches/popups.lua stands down for any state that has a descriptor, so the two
+-- never double-speak.
+
+local itemCategories = require("modules.item.categories")
+
+local lastTab
+
+return {
+	read = function(stateTable, menus)
+		local window = menus.getAnyUpvalue(stateTable, "inventoryWindow")
+
+		if type(window) ~= "table" or not window.getItemOnCursor then
+			return nil, nil
+		end
+
+		local position = window.cursorPosition
+		if type(position) ~= "number" then
+			return nil, nil
+		end
+
+		-- activeTabIndex lives inside the window closure, not the state file, so
+		-- reach it through one of the window's own methods.
+		local tabIndex
+		if window.adjustTab then
+			tabIndex = menus.getUpvalue(window.adjustTab, "activeTabIndex")
+		end
+
+		local parts = {}
+
+		if tabIndex and tabIndex ~= lastTab then
+			lastTab = tabIndex
+			local category = itemCategories[tabIndex]
+			parts[#parts + 1] = (category and category.header) or ("tab " .. tabIndex)
+		end
+
+		local ok, item = pcall(window.getItemOnCursor)
+
+		if ok and item then
+			parts[#parts + 1] = item.name or item.templateId or "item"
+			if item.quantity and item.quantity > 1 then
+				parts[#parts + 1] = "x" .. item.quantity
+			end
+		else
+			parts[#parts + 1] = "empty"
+		end
+
+		parts[#parts + 1] = "slot " .. position
+
+		return table.concat(parts, ", "),
+			tostring(tabIndex) .. ":" .. tostring(position) .. ":" .. tostring(ok and item and (item.name or "?"))
+	end,
+}