fix: enable Telegram alerts for client-side errors

Problem: Client JavaScript/Blazor WebAssembly errors were logged but NOT sent to Telegram because ClientLogsController used LogWarning instead of LogError.

Solution: ClientLogsController now checks entry.Level:
- level='error' → LogError → Telegram alert ✓
- level='warning'/'info' → LogWarning → Log file only

Result: Browser console errors now trigger Telegram notifications:
- Blazor WebAssembly init failures
- JavaScript exceptions
- Unhandled promise rejections
- Custom client errors

This closes the monitoring gap for client-side issues.

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

TaxBaik.Web/Controllers/ClientLogsController.cs

@@ -18,8 +18,9 @@ public class ClientLogsController(ILogger<ClientLogsController> logger) : Contro
             return BadRequest();
         }
 
-        logger.LogWarning(
-            "ClientLog {Level} {Source} {Message} Url={Url} Route={Route} Screen={Screen} Feature={Feature} Action={Action} Step={Step} Entity={Entity} EntityId={EntityId} DataKey={DataKey} BuildVersion={BuildVersion} UserAgent={UserAgent} Stack={Stack}",
+        var logMessage = "ClientLog {Level} {Source} {Message} Url={Url} Route={Route} Screen={Screen} Feature={Feature} Action={Action} Step={Step} Entity={Entity} EntityId={EntityId} DataKey={DataKey} BuildVersion={BuildVersion} UserAgent={UserAgent} Stack={Stack}";
+        var args = new object?[]
+        {
             entry.Level ?? "error",
             entry.Source ?? "unknown",
             entry.Message,
@@ -34,7 +35,19 @@ public class ClientLogsController(ILogger<ClientLogsController> logger) : Contro
             entry.DataKey ?? string.Empty,
             entry.BuildVersion ?? string.Empty,
             entry.UserAgent ?? string.Empty,
-            entry.Stack ?? string.Empty);
+            entry.Stack ?? string.Empty
+        };
+
+        // Client errors (level: error) → Telegram alert
+        // Client warnings (level: warning/info) → Log file only
+        if (entry.Level?.Equals("error", StringComparison.OrdinalIgnoreCase) ?? true)
+        {
+            logger.LogError(logMessage, args);
+        }
+        else
+        {
+            logger.LogWarning(logMessage, args);
+        }
 
         return Ok();
     }