Drop opencode and supermaven, fix prettier, move path-copy keymaps

- Remove the opencode.nvim and supermaven-nvim plugin specs.
- formatting.lua: stop hardcoding prettier's path. It pointed at
  mise/installs/node/22.20.0, which no longer exists (now 24.19.0), so
  conform silently failed to format. Dropping `command` lets conform
  inherit its built-in definition and resolve prettier on PATH, which
  mason.nvim populates.
- keymaps.lua: move the file-path copy maps from <leader>cy/cY to
  <leader>yp/yP.
- Pick up Omarchy Quattro's remote_clipboard.lua and the news-alert
  suppression, plus the lazy-lock/lazyvim.json churn from the upgrade.

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

lazyvim.json

@@ -1,9 +1,11 @@
 {
   "extras": [
-    "lazyvim.plugins.extras.ai.copilot",
     "lazyvim.plugins.extras.lang.astro",
+    "lazyvim.plugins.extras.lang.json",
     "lazyvim.plugins.extras.lang.markdown",
-    "lazyvim.plugins.extras.lang.tailwind"
+    "lazyvim.plugins.extras.lang.sql",
+    "lazyvim.plugins.extras.lang.tailwind",
+    "lazyvim.plugins.extras.lang.toml"
   ],
   "install_version": 8,
   "news": {