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/internal/handler/brief.go

@@ -3,9 +3,13 @@ package handler
 import "github.com/gofiber/fiber/v2"
 
 func Brief(c *fiber.Ctx) error {
-	return c.Render("brief", fiber.Map{
+	data := fiber.Map{
 		"View":     "brief",
 		"Title":    "Quick Brief",
 		"NavItems": navItems,
-	})
+	}
+	if c.Get("HX-Request") != "" {
+		return c.Render("brief_content", data)
+	}
+	return c.Render("brief", data)
 }