feat: expand binary detection to include common Linux file types

Co-authored-by: aider (openai/andrew/openrouter/qwen/qwen3-coder) <aider@aider.chat>

src/meta_plugin/system.rs

@@ -82,11 +82,26 @@ impl BinaryMetaPlugin {
             if data.len() >= 4 {
                 // Check for common binary file headers
                 let headers = [
+                    // Image formats
                     &[0x89, 0x50, 0x4E, 0x47], // PNG
                     &[0xFF, 0xD8, 0xFF, 0xE0], // JPEG
+                    &[0x47, 0x49, 0x46, 0x38], // GIF
+                    &[0x42, 0x4D],             // BMP
+                    // Document formats
                     &[0x25, 0x50, 0x44, 0x46], // PDF
+                    // Archive formats
                     &[0x50, 0x4B, 0x03, 0x04], // ZIP
                     &[0x52, 0x61, 0x72, 0x21], // RAR
+                    &[0x1F, 0x8B],             // GZIP
+                    &[0x42, 0x5A, 0x68],       // BZIP2
+                    &[0xFD, 0x37, 0x7A, 0x58, 0x5A, 0x00], // XZ
+                    // TAR has no magic number, but we can check for common patterns
+                    // Executables and object files
+                    &[0x7F, 0x45, 0x4C, 0x46], // ELF
+                    &[0x4D, 0x5A],             // Windows PE
+                    // Compressed formats
+                    &[0x1F, 0x9D],             // LZW compressed
+                    &[0x1F, 0xA0],             // LZH compressed
                 ];
                 
                 for header in &headers {
@@ -94,6 +109,28 @@ impl BinaryMetaPlugin {
                         return true; // Definitely binary
                     }
                 }
+                
+                // Special case for TAR files (no consistent magic number)
+                // Check if it looks like a TAR header
+                if data.len() >= 512 {
+                    // TAR headers have specific structure
+                    // First 100 bytes are filename (null-terminated)
+                    // Next 8 bytes are file mode (octal, null-terminated)
+                    // If we see this pattern, it's likely a TAR file
+                    let has_tar_structure = 
+                        data[0] != 0 && // First byte of filename should not be null
+                        data[100] == 0 && // File mode should start with null
+                        data[101] >= b'0' && data[101] <= b'7'; // File mode should be octal digit
+                    
+                    if has_tar_structure {
+                        return true;
+                    }
+                }
+            }
+            
+            // Check for AR format (used for static libraries)
+            if data.len() >= 8 && &data[0..8] == b"!<arch>\n" {
+                return true;
             }
             
             // Count printable characters as a fallback