fix: fix online mode after offline-first architecture changes

- Fix nil pointer dereference in PricingHandler alert methods
- Add automatic MariaDB connection on startup if settings exist
- Update setupRouter to accept mariaDB as parameter
- Fix offline mode checks: use h.db instead of h.alertService
- Update setup handler to show restart required message
- Add warning status support in setup.html UI

This ensures that after saving connection settings, the application
works correctly in online mode after restart. All repositories are
properly initialized with MariaDB connection on startup.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

internal/handlers/pricing.go

@@ -639,6 +639,18 @@ func (h *PricingHandler) RecalculateAll(c *gin.Context) {
 }
 
 func (h *PricingHandler) ListAlerts(c *gin.Context) {
+	// Check if we're in offline mode
+	if h.db == nil {
+		c.JSON(http.StatusOK, gin.H{
+			"alerts":   []interface{}{},
+			"total":    0,
+			"page":     1,
+			"per_page": 20,
+			"offline":  true,
+		})
+		return
+	}
+
 	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
 	perPage, _ := strconv.Atoi(c.DefaultQuery("per_page", "20"))
 
@@ -664,6 +676,15 @@ func (h *PricingHandler) ListAlerts(c *gin.Context) {
 }
 
 func (h *PricingHandler) AcknowledgeAlert(c *gin.Context) {
+	// Check if we're in offline mode
+	if h.db == nil {
+		c.JSON(http.StatusServiceUnavailable, gin.H{
+			"error":   "Управление алертами доступно только в онлайн режиме",
+			"offline": true,
+		})
+		return
+	}
+
 	id, err := strconv.ParseUint(c.Param("id"), 10, 32)
 	if err != nil {
 		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid alert id"})
@@ -679,6 +700,15 @@ func (h *PricingHandler) AcknowledgeAlert(c *gin.Context) {
 }
 
 func (h *PricingHandler) ResolveAlert(c *gin.Context) {
+	// Check if we're in offline mode
+	if h.db == nil {
+		c.JSON(http.StatusServiceUnavailable, gin.H{
+			"error":   "Управление алертами доступно только в онлайн режиме",
+			"offline": true,
+		})
+		return
+	}
+
 	id, err := strconv.ParseUint(c.Param("id"), 10, 32)
 	if err != nil {
 		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid alert id"})
@@ -694,6 +724,15 @@ func (h *PricingHandler) ResolveAlert(c *gin.Context) {
 }
 
 func (h *PricingHandler) IgnoreAlert(c *gin.Context) {
+	// Check if we're in offline mode
+	if h.db == nil {
+		c.JSON(http.StatusServiceUnavailable, gin.H{
+			"error":   "Управление алертами доступно только в онлайн режиме",
+			"offline": true,
+		})
+		return
+	}
+
 	id, err := strconv.ParseUint(c.Param("id"), 10, 32)
 	if err != nil {
 		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid alert id"})

internal/handlers/setup.go

@@ -3,12 +3,14 @@ package handlers
 import (
 	"fmt"
 	"html/template"
+	"log/slog"
 	"net/http"
 	"path/filepath"
 	"strconv"
 	"time"
 
 	"github.com/gin-gonic/gin"
+	"git.mchus.pro/mchus/quoteforge/internal/db"
 	"git.mchus.pro/mchus/quoteforge/internal/localdb"
 	"gorm.io/driver/mysql"
 	"gorm.io/gorm"
@@ -17,11 +19,12 @@ import (
 
 type SetupHandler struct {
 	localDB    *localdb.LocalDB
+	connMgr    *db.ConnectionManager
 	templates  map[string]*template.Template
 	restartSig chan struct{}
 }
 
-func NewSetupHandler(localDB *localdb.LocalDB, templatesPath string, restartSig chan struct{}) (*SetupHandler, error) {
+func NewSetupHandler(localDB *localdb.LocalDB, connMgr *db.ConnectionManager, templatesPath string, restartSig chan struct{}) (*SetupHandler, error) {
 	funcMap := template.FuncMap{
 		"sub": func(a, b int) int { return a - b },
 		"add": func(a, b int) int { return a + b },
@@ -39,6 +42,7 @@ func NewSetupHandler(localDB *localdb.LocalDB, templatesPath string, restartSig
 
 	return &SetupHandler{
 		localDB:    localDB,
+		connMgr:    connMgr,
 		templates:  templates,
 		restartSig: restartSig,
 	}, nil
@@ -181,12 +185,23 @@ func (h *SetupHandler) SaveConnection(c *gin.Context) {
 		return
 	}
 
+	// Try to connect immediately to verify settings
+	if h.connMgr != nil {
+		if err := h.connMgr.TryConnect(); err != nil {
+			slog.Warn("failed to connect after saving settings", "error", err)
+		} else {
+			slog.Info("successfully connected to database after saving settings")
+		}
+	}
+
+	// Always restart to properly initialize all services with the new connection
 	c.JSON(http.StatusOK, gin.H{
 		"success": true,
-		"message": "Settings saved. Restarting application...",
+		"message": "Settings saved. Please restart the application to apply changes.",
+		"restart_required": true,
 	})
 
-	// Signal restart after response is sent
+	// Signal restart after response is sent (if restart signal is configured)
 	if h.restartSig != nil {
 		go func() {
 			time.Sleep(500 * time.Millisecond) // Give time for response to be sent