feat: rewrite to stateless web app with IndexedDB frontend

Replace CLI + SQLite architecture with a Go web server + vanilla JS
frontend using IndexedDB for all client-side data storage.

- Remove: cli, store, report, static packages
- Add: compute engine (BuildDashboard), server package, web UI
- Add: setup page with CRUD for profiles, rooms, devices, occupants, AC
- Add: dashboard with SVG temperature timeline, risk analysis, care checklist
- Add: i18n support (English/German) with server-side Go templates
- Add: LLM provider selection UI with client-side API key storage
- Add: per-room indoor temperature, edit buttons, language-aware AI summary

cmd/heatguard/main.go

@@ -0,0 +1,39 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+	"os"
+
+	"github.com/cnachtigall/heatwave-autopilot/internal/config"
+	"github.com/cnachtigall/heatwave-autopilot/internal/server"
+	"github.com/cnachtigall/heatwave-autopilot/web"
+)
+
+func main() {
+	port := flag.Int("port", 8080, "HTTP port")
+	dev := flag.Bool("dev", false, "development mode (serve from filesystem)")
+	flag.Parse()
+
+	cfg := config.Load()
+
+	// Set the embedded filesystem for the server package
+	server.WebFS = web.FS
+
+	srv, err := server.New(server.Options{
+		Port:    *port,
+		DevMode: *dev,
+		Config:  cfg,
+	})
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		os.Exit(1)
+	}
+
+	addr := fmt.Sprintf(":%d", *port)
+	log.Printf("HeatGuard listening on http://localhost%s", addr)
+	if err := srv.ListenAndServe(addr); err != nil {
+		log.Fatal(err)
+	}
+}

cmd/heatwave/main.go

@@ -1,13 +0,0 @@
-package main
-
-import (
-	"os"
-
-	"github.com/cnachtigall/heatwave-autopilot/internal/cli"
-)
-
-func main() {
-	if err := cli.Execute(); err != nil {
-		os.Exit(1)
-	}
-}