Fix iPod transfer: create Music/F00 dir and iTunesCDB on first run

- copy_track_to_ipod: create target directory via os.makedirs
- sync_itunescdb: create iTunesCDB from scratch if missing
- sync_itunescdb: create iTunesCDB.ext with hash if missing

src/ipod_nano7_db.py

@@ -206,6 +206,7 @@ class Nano7Database:
 
         target_dir = self.find_free_music_dir()
         target_path = os.path.join(self.music_base, target_dir, new_name)
+        os.makedirs(os.path.dirname(target_path), exist_ok=True)
         shutil.copy2(filepath, target_path)
 
         relative_path = f"{target_dir}/{new_name}"
@@ -1102,37 +1103,48 @@ class Nano7Database:
         # Compute new SHA1 hash
         new_hash = hashlib.sha1(lib_data).hexdigest()
         
-        # Read existing iTunesCDB to extract the header (first 244 bytes)
+        # Read existing iTunesCDB to extract the header (first bytes before zlib)
-        with open(self.cdb_path, "rb") as f:
+        if not os.path.exists(self.cdb_path):
-            cdb_data = f.read()
+            header = b"\x00" * 244
-        
+            header = b"mhfd" + struct.pack("<I", 244) + header[8:]
-        # Find zlib header (0x78 0x9c is most common, but also check 0x78 0xda and 0x78 0x01)
+            compressed = zlib.compress(lib_data)
-        zlib_offset = -1
+            with open(self.cdb_path, "wb") as f:
-        for pattern in [b"\x78\x9c", b"\x78\xda", b"\x78\x01", b"\x78\x5e"]:
+                f.write(header + compressed)
-            zlib_offset = cdb_data.find(pattern)
+            logger.info(f"Created iTunesCDB: compressed={len(compressed)} bytes")
-            if zlib_offset >= 0:
+        else:
-                break
+            with open(self.cdb_path, "rb") as f:
-        if zlib_offset == -1:
+                cdb_data = f.read()
-            logger.error("Could not find zlib header in iTunesCDB")
+
-            return
+            # Find zlib header (0x78 0x9c is most common, but also check 0x78 0xda and 0x78 0x01)
-        
+            zlib_offset = -1
-        header = cdb_data[:zlib_offset]
+            for pattern in [b"\x78\x9c", b"\x78\xda", b"\x78\x01", b"\x78\x5e"]:
-        
+                zlib_offset = cdb_data.find(pattern)
-        # Compress Library.itdb
+                if zlib_offset >= 0:
-        compressed = zlib.compress(lib_data)
+                    break
-        
+            if zlib_offset == -1:
-        # Write new iTunesCDB
+                logger.error("Could not find zlib header in iTunesCDB")
-        with open(self.cdb_path, "wb") as f:
+                return
-            f.write(header + compressed)
+
+            header = cdb_data[:zlib_offset]
+
+            # Compress Library.itdb
+            compressed = zlib.compress(lib_data)
+
+            # Write new iTunesCDB
+            with open(self.cdb_path, "wb") as f:
+                f.write(header + compressed)
         
         # Update hash in iTunesCDB.ext
-        with open(self.cdb_ext_path, "r") as f:
+        if not os.path.exists(self.cdb_ext_path):
-            ext_content = f.read()
+            ext_content = f"[iTunesCDB]\nitunesdb_hash={new_hash}\n"
-        
+        else:
+            with open(self.cdb_ext_path, "r") as f:
+                ext_content = f.read()
+
         new_ext_content = re.sub(r"itunesdb_hash=\w+", f"itunesdb_hash={new_hash}", ext_content)
         with open(self.cdb_ext_path, "w") as f:
             f.write(new_ext_content)
-        
+
         logger.info(f"Synced iTunesCDB: hash={new_hash}, compressed={len(compressed)} bytes")
 
     def sync_locations_cbk(self):