feat(tools): pick among interchangeable language servers for every language (#313)

A language server and the fallback servers after it in languages/*.toml now share one picker in the Language Servers details pane, for every language rather than Python only: Language server for <languages>: Automatic, each server (with its status) or None, with the Automatic order in the hint. Servers outside such a group keep their on/off checkbox. ToolInfo.alternatives lists each server's group in preference order; a regular server after a fallback starts no group with it. The Python-only picker at the top of the page is removed, and names drop a language suffix the label already states. Storage is unchanged (each server's enabled flag, global or project scope), so existing settings carry over.

src/features/tools/LanguageServersPage.module.css

@@ -11,21 +11,6 @@
   max-width: 680px;
   color: var(--fg-secondary);
 }
-.pythonAnalyzer {
-  display: flex;
-  flex-direction: column;
-  gap: 4px;
-}
-.pythonAnalyzerRow {
-  display: flex;
-  align-items: center;
-  gap: 10px;
-}
-.pythonAnalyzerHint {
-  margin: 0;
-  color: var(--fg-secondary);
-  font-size: var(--fs-small);
-}
 .body {
   display: flex;
   flex: 1;