fix(lsp): handle errors and add missing client filters (#6900)

- Add nil-check when no LSP client is found matching the filter
- Add error handling with pcall for exec_cmd failures
- Add client filter to typescript.goToSourceDefinition and typescript.findAllFileReferences
- Show warning notification when command execution fails or client not found

This fixes the issue where LSP commands would fail silently or cause crashes when
executing on unfiltered clients, and where irrelevant LSP clients (like Copilot)
would report errors for unsupported commands.

lua/lazyvim/plugins/extras/lang/typescript.lua

@@ -72,6 +72,7 @@ return {
                 local win = vim.api.nvim_get_current_win()
                 local params = vim.lsp.util.make_position_params(win, "utf-16")
                 LazyVim.lsp.execute({
+                  filter = "vtsls",
                   command = "typescript.goToSourceDefinition",
                   arguments = { params.textDocument.uri, params.position },
                   open = true,
@@ -83,6 +84,7 @@ return {
               "gR",
               function()
                 LazyVim.lsp.execute({
+                  filter = "vtsls",
                   command = "typescript.findAllFileReferences",
                   arguments = { vim.uri_from_bufnr(0) },
                   open = true,

lua/lazyvim/util/lsp.lua

@@ -76,7 +76,14 @@ function M.execute(opts)
   local buf = vim.api.nvim_get_current_buf()
 
   ---@cast filter vim.lsp.get_clients.Filter
-  local client = vim.lsp.get_clients(LazyVim.merge({}, filter, { bufnr = buf }))[1]
+  local clients = vim.lsp.get_clients(LazyVim.merge({}, filter, { bufnr = buf }))
+  local client = clients[1]
+
+  if not client then
+    local filter_name = type(opts.filter) == "string" and opts.filter or (filter.name or "any")
+    LazyVim.warn("No LSP client found for filter: " .. filter_name, { title = "LSP Execute" })
+    return
+  end
 
   local params = {
     command = opts.command,
@@ -89,7 +96,14 @@ function M.execute(opts)
     })
   else
     vim.list_extend(params, { title = opts.title })
-    return client:exec_cmd(params, { bufnr = buf }, opts.handler)
+    local ok, result = pcall(function()
+      return client:exec_cmd(params, { bufnr = buf }, opts.handler)
+    end)
+    if not ok then
+      LazyVim.warn("Failed to execute command '" .. opts.command .. "': " .. tostring(result), { title = "LSP Execute" })
+      return
+    end
+    return result
   end
 end