Restructure modules with per-module addon subdirs

- Each module (outline, interact, screenshot) now has its own addon/
  subdir with .toc, .lua, and Bindings.xml
- Core WeirdUtils addon lives in src/core/addon/
- build.zig supports compile-time feature gating via -D options
- main.zig uses build_options for conditional imports and addon embedding
- Module addons only load when their module is compiled in
- 'zig build all-variants' produces full.dll + 3 single-module DLLs

src/screenshot/addon/Screenshot.lua

@@ -0,0 +1,46 @@
+-- Screenshot addon (embedded in DLL, loaded from memory)
+-- Part of WeirdUtils - only loaded when screenshot module is compiled
+
+SCREENSHOT_VERSION = 1
+
+BINDING_HEADER_SCREENSHOT = "Screenshot"
+
+local frame = CreateFrame("Frame")
+frame:RegisterEvent("ADDON_LOADED")
+frame:RegisterEvent("PLAYER_LOGIN")
+
+frame:SetScript("OnEvent", function()
+    if event == "PLAYER_LOGIN" then
+        local on, level = WeirdUtilsScreenshot()
+        DEFAULT_CHAT_FRAME:AddMessage("|cff00ff00Screenshot|r v" .. SCREENSHOT_VERSION .. " loaded (" .. (on and "enabled" or "disabled") .. ", quality " .. level .. ")")
+    end
+end)
+
+SLASH_SCREENSHOT1 = "/ss"
+SLASH_SCREENSHOT2 = "/screenshot"
+SlashCmdList["SCREENSHOT"] = function(msg)
+    msg = string.lower(msg or "")
+    if msg == "" or msg == "status" then
+        local on, level = WeirdUtilsScreenshot()
+        DEFAULT_CHAT_FRAME:AddMessage("Screenshots: " .. (on and "|cff00ff00ON|r" or "|cffff0000OFF|r") .. " (quality " .. level .. ")")
+    elseif msg == "on" or msg == "enable" then
+        WeirdUtilsScreenshot("enable")
+        DEFAULT_CHAT_FRAME:AddMessage("Screenshots |cff00ff00enabled|r")
+    elseif msg == "off" or msg == "disable" then
+        WeirdUtilsScreenshot("disable")
+        DEFAULT_CHAT_FRAME:AddMessage("Screenshots |cffff0000disabled|r")
+    elseif tonumber(msg) then
+        local q = tonumber(msg)
+        if q >= 0 and q <= 9 then
+            WeirdUtilsScreenshot("quality", q)
+            DEFAULT_CHAT_FRAME:AddMessage("Screenshot quality: " .. q)
+        else
+            DEFAULT_CHAT_FRAME:AddMessage("|cffff0000Quality must be 0-9|r")
+        end
+    else
+        DEFAULT_CHAT_FRAME:AddMessage("|cff00ff00Screenshot|r commands:")
+        DEFAULT_CHAT_FRAME:AddMessage("  /ss - Show status")
+        DEFAULT_CHAT_FRAME:AddMessage("  /ss on|off - Enable/disable PNG screenshots")
+        DEFAULT_CHAT_FRAME:AddMessage("  /ss 0-9 - Set compression level (0=fast, 9=small)")
+    end
+end