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.

Models/ParallelOptions.cs

@@ -0,0 +1,8 @@
+namespace OpenQuery.Models;
+
+public class ParallelProcessingOptions
+{
+    public int MaxConcurrentArticleFetches { get; set; } = 10;
+    public int MaxConcurrentEmbeddingRequests { get; set; } = 4;
+    public int EmbeddingBatchSize { get; set; } = 300;
+}