Add mac-cursor-ring.lua: show the Mac pointer in the VNC mirror

macOS leaves the pointer out of the Screen Sharing framebuffer, and neither Remmina showcursor setting brings it back. A Hammerspoon ring around the pointer is a real window, so it gets mirrored.

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

scripts/mac-cursor-ring.lua

@@ -0,0 +1,40 @@
+-- Hammerspoon: draw a ring around the Mac pointer so it shows in the VNC
+-- mirror on the Frame. macOS Screen Sharing leaves the pointer out of the
+-- framebuffer; a real on-screen window is captured like anything else.
+--
+-- Install: brew install --cask hammerspoon, then in ~/.hammerspoon/init.lua:
+--   dofile("/path/to/frame-control/scripts/mac-cursor-ring.lua")
+-- Toggle: ctrl+alt+cmd+M. Polls the pointer position, so no Accessibility
+-- permission is needed.
+
+local SIZE, WIDTH = 34, 3
+local COLOR = { red = 1, green = 0.2, blue = 0.2, alpha = 0.9 }
+
+local ring = hs.canvas.new({ x = 0, y = 0, w = SIZE, h = SIZE })
+ring:appendElements({
+  type = "circle", action = "stroke",
+  strokeColor = COLOR, strokeWidth = WIDTH,
+  radius = (SIZE - WIDTH) / 2,
+})
+ring:level(hs.canvas.windowLevels.cursor)
+ring:behavior({ "canJoinAllSpaces", "stationary", "ignoresCycle" })
+
+local last = {}
+local function follow()
+  local p = hs.mouse.absolutePosition()
+  if p.x ~= last.x or p.y ~= last.y then
+    ring:topLeft({ x = p.x - SIZE / 2, y = p.y - SIZE / 2 })
+    last = p
+  end
+end
+
+frameCursorRing = { canvas = ring, timer = hs.timer.new(1 / 60, follow) }
+
+local function show() follow(); ring:show(); frameCursorRing.timer:start() end
+local function hide() frameCursorRing.timer:stop(); ring:hide() end
+
+hs.hotkey.bind({ "ctrl", "alt", "cmd" }, "M", function()
+  if ring:isShowing() then hide() else show() end
+end)
+
+show()