fix: replace deprecated vim.loop with vim.uv

Problem: vim.loop is deprecated since Neovim 0.10 in favour of vim.uv.
Five call sites across scraper.lua, setup.lua, utils.lua, and health.lua
still referenced the old alias.

Solution: replace every vim.loop reference with vim.uv directly.

lua/cp/scraper.lua

@@ -57,7 +57,7 @@ local function run_scraper(platform, subcommand, args, opts)
   env.CONDA_PREFIX = ''
 
   if opts and opts.ndjson then
-    local uv = vim.loop
+    local uv = vim.uv
     local stdout = uv.new_pipe(false)
     local stderr = uv.new_pipe(false)
     local buf = ''