Add report logos and configurable folder scan depth

Report branding (top-left MSP logo, top-right client logo):
- Add MspLogo to AppSettings; client logo already on TenantProfile
- IUserSessionService.CurrentBranding composes MSP + active profile logo
- New reusable LogoUpload component (InputFile -> base64 LogoData, 512KB cap)
- MSP logo upload in Settings; optional client logo in profile create/edit
- Wire ReportBranding into all 6 HTML export pages
- Fix EditProfile dropping ClientLogo on edit

Storage metrics: expose folder scan depth (0-20) in scan options UI,
passed to existing StorageScanOptions.FolderDepth recursion.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Services/Session/IUserSessionService.cs

@@ -12,6 +12,9 @@ public interface IUserSessionService
     bool HasProfile { get; }
     AppSettings Settings { get; }
 
+    /// <summary>Branding for exported reports: MSP logo (settings) + active profile's client logo.</summary>
+    ReportBranding CurrentBranding { get; }
+
     void SetProfile(TenantProfile profile);
     Task ClearSessionAsync();
     void UpdateSettings(AppSettings settings);