refactor: absorb statusline offset into indicator padding

Remove the hardcoded statusline_offset from calculate_position() and
let padding.y serve as the sole offset from the bottom edge. Bump
default padding.y to 3 to preserve the original visual position.

lua/watchexec/indicator.lua

@@ -36,20 +36,19 @@ local function calculate_position()
   local width = cfg.width or 2
   local height = cfg.height or 1
   local pad_x = cfg.padding and cfg.padding.x or 1
-  local pad_y = cfg.padding and cfg.padding.y or 1
-  local statusline_offset = 2
+  local pad_y = cfg.padding and cfg.padding.y or 3
 
   if cfg.position == "bottom-left" then
-    return vim.o.lines - height - statusline_offset, pad_x
+    return vim.o.lines - height - pad_y, pad_x
   elseif cfg.position == "bottom-right" then
-    return vim.o.lines - height - statusline_offset, vim.o.columns - width - pad_x
+    return vim.o.lines - height - pad_y, vim.o.columns - width - pad_x
   elseif cfg.position == "top-left" then
     return pad_y, pad_x
   elseif cfg.position == "top-right" then
     return pad_y, vim.o.columns - width - pad_x
   end
 
-  return vim.o.lines - height - statusline_offset, pad_x
+  return vim.o.lines - height - pad_y, pad_x
 end
 
 local function close_float()