fix: UI overhaul — align all HTMX views with Lumina Design System (46 fixes)

- All 7 pages rewritten: Dashboard, Terminal, Snippets, Keychain, SFTP, Settings, Brief
- Apply consistent Lumina glassmorphic theme (rounded-2xl, shadows, borders, tracking)
- Fix SVG icons not rendering — return template.HTML instead of string
- Fix Alpine x-data scoping: terminal tabs, SFTP modals, snippet tag buttons
- Fix dashboard search sending literal ?q=...
- Rebuild CSS with all new Tailwind classes (62KB)
- Add .air.toml with hot-reload config, docs/PERBAIKANUI.md checklist
- Remove unused backup partials

app/backend/.air.toml

@@ -0,0 +1,35 @@
+root = "."
+tmp_dir = "tmp"
+
+[build]
+  cmd = "go build -o ./tmp/backend main.go"
+  full_bin = "./tmp/backend"
+  delay = 200
+  exclude_dir = ["assets", "tmp", "vendor", "node_modules"]
+  exclude_file = []
+  exclude_regex = []
+  exclude_unchanged = false
+  follow_symlink = false
+  include_dir = ["internal", "views", "static", "."]
+  include_ext = ["go", "html", "css", "js"]
+  include_file = ["main.go"]
+  kill_delay = "0s"
+  log = "build-errors.log"
+  send_interrupt = false
+  stop_on_error = false
+
+[color]
+  app = ""
+  build = "yellow"
+  main = "green"
+  runner = "cyan"
+  watcher = "blue"
+
+[log]
+  time = false
+
+[misc]
+  clean_on_exit = true
+
+[screen]
+  clear_on_rebuild = false