添加api调用接口

Co-authored-by: Copilot <copilot@github.com>

app/utils/gcode_parser.py

@@ -0,0 +1,32 @@
+import os
+
+def get_gcode_metadata(filepath):
+    metadata = {
+        'print_time': '-',
+        'first_layer_time': '-',
+        'filament_used': '-'
+    }
+    if not os.path.exists(filepath):
+        return metadata
+        
+    try:
+        # Read the last few KB to find estimated time and filament used
+        with open(filepath, 'rb') as f:
+            f.seek(0, 2)
+            file_size = f.tell()
+            chunk_size = min(65536, file_size)  # read last 64KB
+            f.seek(file_size - chunk_size)
+            chunk = f.read().decode('utf-8', errors='ignore')
+            
+            lines = chunk.splitlines()
+            for line in reversed(lines):
+                if line.startswith('; estimated printing time (normal mode) ='):
+                    metadata['print_time'] = line.split('=')[1].strip()
+                elif line.startswith('; estimated first layer printing time (normal mode) ='):
+                    metadata['first_layer_time'] = line.split('=')[1].strip()
+                elif line.startswith('; filament used [mm] ='):
+                    metadata['filament_used'] = line.split('=')[1].strip()
+    except Exception:
+        pass
+        
+    return metadata