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

internal/server/server_test.go

@@ -0,0 +1,167 @@
+package server
+
+import (
+	"bytes"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"testing"
+
+	"github.com/cnachtigall/heatwave-autopilot/internal/compute"
+	"github.com/cnachtigall/heatwave-autopilot/internal/config"
+)
+
+func TestMain(m *testing.M) {
+	// Tests run from the package directory. Set WebFS to point to web/ dir.
+	WebFS = os.DirFS("../../web")
+	os.Exit(m.Run())
+}
+
+func testServer(t *testing.T) *Server {
+	t.Helper()
+	s, err := New(Options{
+		Port:    0,
+		DevMode: false,
+		Config:  config.DefaultConfig(),
+	})
+	if err != nil {
+		t.Fatalf("create server: %v", err)
+	}
+	return s
+}
+
+func TestDashboardPage(t *testing.T) {
+	s := testServer(t)
+	req := httptest.NewRequest("GET", "/", nil)
+	w := httptest.NewRecorder()
+	s.Handler().ServeHTTP(w, req)
+	if w.Code != http.StatusOK {
+		t.Errorf("got status %d, want 200; body: %s", w.Code, w.Body.String())
+	}
+	if ct := w.Header().Get("Content-Type"); ct != "text/html; charset=utf-8" {
+		t.Errorf("got content-type %q, want text/html", ct)
+	}
+}
+
+func TestSetupPage(t *testing.T) {
+	s := testServer(t)
+	req := httptest.NewRequest("GET", "/setup", nil)
+	w := httptest.NewRecorder()
+	s.Handler().ServeHTTP(w, req)
+	if w.Code != http.StatusOK {
+		t.Errorf("got status %d, want 200; body: %s", w.Code, w.Body.String())
+	}
+}
+
+func TestGuidePage(t *testing.T) {
+	s := testServer(t)
+	req := httptest.NewRequest("GET", "/guide", nil)
+	w := httptest.NewRecorder()
+	s.Handler().ServeHTTP(w, req)
+	if w.Code != http.StatusOK {
+		t.Errorf("got status %d, want 200; body: %s", w.Code, w.Body.String())
+	}
+}
+
+func TestNotFound(t *testing.T) {
+	s := testServer(t)
+	req := httptest.NewRequest("GET", "/nonexistent", nil)
+	w := httptest.NewRecorder()
+	s.Handler().ServeHTTP(w, req)
+	if w.Code != http.StatusNotFound {
+		t.Errorf("got status %d, want 404", w.Code)
+	}
+}
+
+func TestLanguageDetection(t *testing.T) {
+	s := testServer(t)
+
+	req := httptest.NewRequest("GET", "/?lang=de", nil)
+	w := httptest.NewRecorder()
+	s.Handler().ServeHTTP(w, req)
+	if w.Code != http.StatusOK {
+		t.Errorf("got status %d, want 200", w.Code)
+	}
+	body := w.Body.String()
+	if !bytes.Contains([]byte(body), []byte(`lang="de"`)) {
+		t.Error("expected lang=de in response")
+	}
+
+	cookies := w.Result().Cookies()
+	found := false
+	for _, c := range cookies {
+		if c.Name == "heatguard_lang" && c.Value == "de" {
+			found = true
+		}
+	}
+	if !found {
+		t.Error("expected heatguard_lang cookie to be set")
+	}
+}
+
+func TestComputeAPI_NoForecasts(t *testing.T) {
+	s := testServer(t)
+
+	reqBody := compute.ComputeRequest{
+		Profile: compute.Profile{Name: "Test", Timezone: "UTC"},
+		Date:    "2025-07-15",
+	}
+	b, _ := json.Marshal(reqBody)
+
+	req := httptest.NewRequest("POST", "/api/compute/dashboard", bytes.NewReader(b))
+	req.Header.Set("Content-Type", "application/json")
+	w := httptest.NewRecorder()
+	s.Handler().ServeHTTP(w, req)
+	if w.Code != http.StatusBadRequest {
+		t.Errorf("got status %d, want 400", w.Code)
+	}
+}
+
+func TestComputeAPI_MethodNotAllowed(t *testing.T) {
+	s := testServer(t)
+	req := httptest.NewRequest("GET", "/api/compute/dashboard", nil)
+	w := httptest.NewRecorder()
+	s.Handler().ServeHTTP(w, req)
+	if w.Code != http.StatusMethodNotAllowed {
+		t.Errorf("got status %d, want 405", w.Code)
+	}
+}
+
+func TestLLMConfigAPI(t *testing.T) {
+	s := testServer(t)
+	req := httptest.NewRequest("GET", "/api/llm/config", nil)
+	w := httptest.NewRecorder()
+	s.Handler().ServeHTTP(w, req)
+	if w.Code != http.StatusOK {
+		t.Errorf("got status %d, want 200", w.Code)
+	}
+
+	var resp struct {
+		Provider  string `json:"provider"`
+		Model     string `json:"model"`
+		Available bool   `json:"available"`
+	}
+	json.NewDecoder(w.Body).Decode(&resp)
+	if resp.Available {
+		t.Errorf("expected available=false for noop provider, got provider=%q model=%q available=%v", resp.Provider, resp.Model, resp.Available)
+	}
+}
+
+func TestLLMSummarize_Noop(t *testing.T) {
+	s := testServer(t)
+	body := `{"date":"2025-07-15","peakTempC":35,"riskLevel":"high"}`
+	req := httptest.NewRequest("POST", "/api/llm/summarize", bytes.NewBufferString(body))
+	req.Header.Set("Content-Type", "application/json")
+	w := httptest.NewRecorder()
+	s.Handler().ServeHTTP(w, req)
+	if w.Code != http.StatusOK {
+		t.Errorf("got status %d, want 200", w.Code)
+	}
+
+	var resp map[string]string
+	json.NewDecoder(w.Body).Decode(&resp)
+	if resp["summary"] != "" {
+		t.Errorf("expected empty summary for noop, got %q", resp["summary"])
+	}
+}