App logs, client settings, NavMenu layout

- Add real-time app logs via SignalR (log level, category filters)
- Add filters modal with restore defaults; sentinel for empty arrays
- Add client settings: max lines and auto-scroll per log panel
- Improve NavMenu: align settings + hamburger, smaller mobile logo
- LogsService, LogsHub, LoggingController, AppLogsLoggerProvider
- Persist log level and filters to appsettings.Overrides.json

src/DnsmasqWebUI/Models/Client/ClientSettings.cs

@@ -8,9 +8,24 @@ public class ClientSettings
     /// <summary>Polling interval for the service status block (seconds).</summary>
     public int ServiceStatusPollingIntervalSeconds { get; set; } = 15;
 
-    /// <summary>Polling interval for the recent logs block (seconds).</summary>
+    /// <summary>Polling interval for the recent dnsmasq logs block (seconds).</summary>
     public int RecentLogsPollingIntervalSeconds { get; set; } = 5;
 
+    /// <summary>Polling interval for the app logs block fallback (seconds).</summary>
+    public int AppLogsPollingIntervalSeconds { get; set; } = 5;
+
     /// <summary>Polling interval for the DHCP leases list (seconds).</summary>
     public int LeasesPollingIntervalSeconds { get; set; } = 5;
+
+    /// <summary>Maximum number of lines in the dnsmasq (recent) logs panel. Older lines are truncated.</summary>
+    public int RecentLogsMaxLines { get; set; } = 500;
+
+    /// <summary>Whether to auto-scroll the dnsmasq logs panel when new lines arrive.</summary>
+    public bool RecentLogsAutoScroll { get; set; } = true;
+
+    /// <summary>Maximum number of lines in the app logs panel. Older lines are truncated.</summary>
+    public int AppLogsMaxLines { get; set; } = 500;
+
+    /// <summary>Whether to auto-scroll the app logs panel when new lines arrive.</summary>
+    public bool AppLogsAutoScroll { get; set; } = true;
 }

src/DnsmasqWebUI/Models/Client/ClientSettingsFields.cs

@@ -0,0 +1,23 @@
+namespace DnsmasqWebUI.Models.Client;
+
+/// <summary>
+/// Per-field metadata for client settings: bounds, display names for validation errors.
+/// Used by SettingsModal (validation on save) and by pages/components (defensive clamp when loading from storage).
+/// </summary>
+public static class ClientSettingsFields
+{
+    public sealed record FieldBounds(int Min, int Max, string DisplayName)
+    {
+        public bool IsValid(int value) => value >= Min && value <= Max;
+        public int Clamp(int value) => Math.Clamp(value, Min, Max);
+        public string? Validate(int value) =>
+            IsValid(value) ? null : $"{DisplayName} must be between {Min} and {Max} seconds. You entered {value}.";
+    }
+
+    public static readonly FieldBounds ServiceStatusPollingInterval = new(5, 300, "Service status polling interval");
+    public static readonly FieldBounds RecentLogsPollingInterval = new(5, 300, "Recent logs polling interval");
+    public static readonly FieldBounds AppLogsPollingInterval = new(5, 300, "App logs polling interval");
+    public static readonly FieldBounds LeasesPollingInterval = new(5, 300, "DHCP leases refresh interval");
+    public static readonly FieldBounds RecentLogsMaxLines = new(100, 2000, "Recent logs max lines");
+    public static readonly FieldBounds AppLogsMaxLines = new(100, 2000, "App logs max lines");
+}

src/DnsmasqWebUI/Models/Client/SettingsModalSections.cs

@@ -11,9 +11,12 @@ public enum SettingsModalContext
     /// <summary>Show only service status polling interval.</summary>
     ServicePolling,
 
-    /// <summary>Show only recent logs polling interval.</summary>
+    /// <summary>Show only recent dnsmasq logs polling interval.</summary>
     LogsPolling,
 
+    /// <summary>Show only app logs polling interval.</summary>
+    AppLogsPolling,
+
     /// <summary>Show only DHCP leases refresh interval.</summary>
     LeasesPolling
 }
@@ -25,7 +28,10 @@ public static class SettingsModalSections
 {
     public const string ServiceStatus = "ServiceStatus";
     public const string Logs = "Logs";
+    public const string AppLogs = "AppLogs";
     public const string Leases = "Leases";
+    public const string RecentLogsDisplay = "RecentLogsDisplay";
+    public const string AppLogsDisplay = "AppLogsDisplay";
 
     /// <summary>Section metadata: display name (header), field label (for input), and searchable text for filtering.</summary>
     public sealed record SectionMeta(string DisplayName, string FieldLabel, string SearchableText);
@@ -33,19 +39,30 @@ public static class SettingsModalSections
     public static readonly IReadOnlyDictionary<string, SectionMeta> All = new Dictionary<string, SectionMeta>(StringComparer.OrdinalIgnoreCase)
     {
         [ServiceStatus] = new("Service status", "Polling interval (seconds)", "service status polling interval seconds"),
-        [Logs] = new("Recent logs", "Polling interval (seconds)", "recent logs polling interval seconds"),
+        [Logs] = new("Recent logs", "Polling interval (seconds)", "recent dnsmasq logs polling interval seconds"),
+        [AppLogs] = new("App logs", "Polling interval (seconds)", "app logs polling interval seconds"),
         [Leases] = new("DHCP leases", "Refresh interval (seconds)", "dhcp leases refresh interval seconds"),
+        [RecentLogsDisplay] = new("Recent logs display", "Max lines / Auto-scroll", "recent logs display max lines auto scroll"),
+        [AppLogsDisplay] = new("App logs display", "Max lines / Auto-scroll", "app logs display max lines auto scroll"),
     };
 
-    /// <summary>Maps a focused context (single-section view) to its section key. Returns null for All.</summary>
-    public static string? GetSectionKeyForContext(SettingsModalContext context) => context switch
+    /// <summary>Maps a focused context (single-section view) to its section keys. Returns null for All (search mode).</summary>
+    public static string[]? GetSectionKeysForContext(SettingsModalContext context) => context switch
     {
-        SettingsModalContext.ServicePolling => ServiceStatus,
-        SettingsModalContext.LogsPolling => Logs,
-        SettingsModalContext.LeasesPolling => Leases,
+        SettingsModalContext.ServicePolling => [ServiceStatus],
+        SettingsModalContext.LogsPolling => [Logs, RecentLogsDisplay],
+        SettingsModalContext.AppLogsPolling => [AppLogs, AppLogsDisplay],
+        SettingsModalContext.LeasesPolling => [Leases],
         _ => null
     };
 
+    /// <summary>Legacy: returns first section key for context. Use GetSectionKeysForContext for multi-section support.</summary>
+    public static string? GetSectionKeyForContext(SettingsModalContext context)
+    {
+        var keys = GetSectionKeysForContext(context);
+        return keys is { Length: > 0 } ? keys[0] : null;
+    }
+
     public static bool MatchesSearch(string key, string searchTerm)
     {
         if (string.IsNullOrWhiteSpace(searchTerm)) return true;