feat: parallel async processing and compact output mode

Major performance improvements:
- Parallel search execution across all queries
- Parallel article fetching with 10 concurrent limit
- Parallel embeddings with rate limiting (4 concurrent)
- Polly integration for retry resilience

New features:
- Add -v/--verbose flag for detailed output
- Compact single-line status mode with braille spinner
- StatusReporter service for unified output handling
- Query generation and errors hidden in compact mode
- ANSI escape codes for clean line updates

New files:
- Services/RateLimiter.cs - Semaphore-based concurrency control
- Services/StatusReporter.cs - Verbose/compact output handler
- Models/ParallelOptions.cs - Parallel processing configuration

All changes maintain Native AOT compatibility.

Services/RateLimiter.cs

@@ -0,0 +1,42 @@
+namespace OpenQuery.Services;
+
+public sealed class RateLimiter : IAsyncDisposable
+{
+    private readonly SemaphoreSlim _semaphore;
+
+    public RateLimiter(int maxConcurrentRequests)
+    {
+        _semaphore = new SemaphoreSlim(maxConcurrentRequests, maxConcurrentRequests);
+    }
+
+    public async Task<T> ExecuteAsync<T>(Func<Task<T>> action, CancellationToken cancellationToken = default)
+    {
+        await _semaphore.WaitAsync(cancellationToken);
+        try
+        {
+            return await action();
+        }
+        finally
+        {
+            _semaphore.Release();
+        }
+    }
+
+    public async Task ExecuteAsync(Func<Task> action, CancellationToken cancellationToken = default)
+    {
+        await _semaphore.WaitAsync(cancellationToken);
+        try
+        {
+            await action();
+        }
+        finally
+        {
+            _semaphore.Release();
+        }
+    }
+
+    public async ValueTask DisposeAsync()
+    {
+        _semaphore.Dispose();
+    }
+}