feat(ui): modernize nvim with fzf-lua, snacks dashboard, and p10k-style statusline

- Replace Snacks picker with fzf-lua for LSP navigation (gd, gr, gi, gt)
- Add fzf-lua plugin with LSP-optimized settings
- Fix Mason inconsistencies (add eslint, gopls to ensure_installed)
- Replace alpha-nvim with Snacks dashboard (shared config)
- Create dashboard_config.lua for DRY dashboard settings
- Modernize lualine with p10k-rainbow style and solid backgrounds
- Enhance bufferline with LSP diagnostics and modern styling
- Update noice with centered cmdline/search and modern icons
- Add global rounded borders for floating windows
- Improve indent-blankline with scope highlighting
- Add return-to-dashboard on last buffer close
- Create performance_monitor module

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

lua/cargdev/core/function/performance_monitor.lua

@@ -0,0 +1,112 @@
+local M = {}
+
+-- Check overall Neovim performance
+function M.check_performance()
+  local stats = {}
+
+  -- Startup time
+  stats.startup = vim.fn.reltimefloat(vim.fn.reltime(vim.g.start_time or vim.fn.reltime()))
+
+  -- Memory usage
+  local mem = collectgarbage("count")
+  stats.memory_kb = math.floor(mem)
+  stats.memory_mb = string.format("%.2f", mem / 1024)
+
+  -- Buffer count
+  stats.buffers = #vim.fn.getbufinfo({ buflisted = 1 })
+
+  -- Loaded plugins (lazy.nvim)
+  local lazy_ok, lazy = pcall(require, "lazy")
+  if lazy_ok then
+    local lazy_stats = lazy.stats()
+    stats.plugins_loaded = lazy_stats.loaded
+    stats.plugins_total = lazy_stats.count
+    stats.startup_ms = string.format("%.2f", lazy_stats.startuptime)
+  end
+
+  -- Active LSP clients
+  stats.lsp_clients = #vim.lsp.get_clients()
+
+  -- Display results
+  local lines = {
+    "Performance Stats",
+    string.rep("-", 40),
+    string.format("Memory Usage: %s MB (%d KB)", stats.memory_mb, stats.memory_kb),
+    string.format("Open Buffers: %d", stats.buffers),
+    string.format("Active LSP Clients: %d", stats.lsp_clients),
+  }
+
+  if stats.plugins_loaded then
+    table.insert(lines, string.format("Plugins: %d/%d loaded", stats.plugins_loaded, stats.plugins_total))
+    table.insert(lines, string.format("Startup Time: %s ms", stats.startup_ms))
+  end
+
+  vim.notify(table.concat(lines, "\n"), vim.log.levels.INFO, { title = "Performance" })
+end
+
+-- Check LSP health for current buffer
+function M.check_lsp_health()
+  local clients = vim.lsp.get_clients({ bufnr = 0 })
+
+  if #clients == 0 then
+    vim.notify("No LSP clients attached to this buffer", vim.log.levels.WARN, { title = "LSP Health" })
+    return
+  end
+
+  local lines = {
+    "LSP Health Report",
+    string.rep("-", 40),
+  }
+
+  for _, client in ipairs(clients) do
+    table.insert(lines, "")
+    table.insert(lines, string.format("Client: %s (id: %d)", client.name, client.id))
+    table.insert(lines, string.format("  Root: %s", client.config.root_dir or "N/A"))
+
+    -- Check capabilities
+    local caps = {}
+    if client.server_capabilities.completionProvider then
+      table.insert(caps, "completion")
+    end
+    if client.server_capabilities.hoverProvider then
+      table.insert(caps, "hover")
+    end
+    if client.server_capabilities.definitionProvider then
+      table.insert(caps, "definition")
+    end
+    if client.server_capabilities.referencesProvider then
+      table.insert(caps, "references")
+    end
+    if client.server_capabilities.documentFormattingProvider then
+      table.insert(caps, "formatting")
+    end
+    if client.server_capabilities.codeActionProvider then
+      table.insert(caps, "code_actions")
+    end
+
+    table.insert(lines, string.format("  Capabilities: %s", table.concat(caps, ", ")))
+  end
+
+  -- Diagnostics summary
+  local diagnostics = vim.diagnostic.get(0)
+  local counts = { errors = 0, warnings = 0, hints = 0, info = 0 }
+  for _, d in ipairs(diagnostics) do
+    if d.severity == vim.diagnostic.severity.ERROR then
+      counts.errors = counts.errors + 1
+    elseif d.severity == vim.diagnostic.severity.WARN then
+      counts.warnings = counts.warnings + 1
+    elseif d.severity == vim.diagnostic.severity.HINT then
+      counts.hints = counts.hints + 1
+    elseif d.severity == vim.diagnostic.severity.INFO then
+      counts.info = counts.info + 1
+    end
+  end
+
+  table.insert(lines, "")
+  table.insert(lines, string.format("Diagnostics: %d errors, %d warnings, %d hints, %d info",
+    counts.errors, counts.warnings, counts.hints, counts.info))
+
+  vim.notify(table.concat(lines, "\n"), vim.log.levels.INFO, { title = "LSP Health" })
+end
+
+return M