test: improve coverage for API, AI, Alerts, and Frontend Utils

- Add comprehensive tests for internal/api/config_handlers.go (Phases 1-3)
- Improve test coverage for AI tools, chat service, and session management
- Enhance alert and notification tests (ResolvedAlert, Webhook)
- Add frontend unit tests for utils (searchHistory, tagColors, temperature, url)
- Add proximity client API tests

internal/api/config_handlers_setup_code_test.go

@@ -0,0 +1,32 @@
+package api
+
+import (
+	"testing"
+
+	"github.com/rcourtman/pulse-go-rewrite/internal/config"
+)
+
+func TestGenerateSetupCode(t *testing.T) {
+	tempDir := t.TempDir()
+	cfg := &config.Config{
+		DataPath:   tempDir,
+		ConfigPath: tempDir,
+	}
+
+	handler := newTestConfigHandlers(t, cfg)
+
+	// Test 1: Basic generation
+	code := handler.generateSetupCode()
+	if len(code) != 32 { // 16 bytes hex encoded = 32 chars
+		t.Errorf("expected code length 32, got %d", len(code))
+	}
+
+	// Verify uniqueness
+	code2 := handler.generateSetupCode()
+	if code == code2 {
+		t.Error("generated codes should be unique (random)")
+	}
+
+	// Storage is handled by HandleSetupScriptURL, not generateSetupCode.
+	// So we don't verify storage here.
+}