Fix timeout for long surahs - dynamic timeout calculation

Issue: 120s timeout too short for long surahs (8+ minutes)
Solution: Calculate timeout dynamically based on video duration

Formula: timeout = max(120, duration * 2 + 60)
- Short videos (1 min): 120s timeout
- Medium videos (5 min): 660s timeout
- Long videos (10 min): 1260s timeout

This ensures FFmpeg has enough time to process subtitles
for any surah length without unnecessary waiting.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

src/video_generator.py

@@ -238,8 +238,12 @@ class VideoGenerator:
         print(f"Command: {' '.join(cmd[:10])}...")  # Print first part to avoid too much logging
 
         try:
+            # Calculate timeout based on video duration (2x duration + 60s buffer, min 120s)
+            timeout = max(120, int(duration * 2 + 60))
+            print(f"Video duration: {duration:.1f}s, timeout: {timeout}s")
+
             # Try with ASS/SRT subtitles
-            result = subprocess.run(cmd, capture_output=True, text=True, timeout=120)
+            result = subprocess.run(cmd, capture_output=True, text=True, timeout=timeout)
         except subprocess.TimeoutExpired:
             print("FFmpeg timeout, falling back to video without subtitles...")
             result = subprocess.CompletedProcess(cmd, 1, "", "Timeout")
@@ -261,7 +265,7 @@ class VideoGenerator:
                 "-movflags", "+faststart",
                 output_path
             ]
-            result = subprocess.run(cmd_simple, capture_output=True, text=True, timeout=120)
+            result = subprocess.run(cmd_simple, capture_output=True, text=True, timeout=timeout)
             if result.returncode != 0:
                 raise Exception(f"Failed to create video: {result.stderr[:500]}")
             print("Warning: Created video without burned-in subtitles")