Implemented initial DLPak design

Implemented DLPak design with zip storage, DLPak consists of two files,
a manifest.json which provides details on the signals, time of recording
and currently blank comment field and data.csv which stores all the
signals as csv with the nanosecond timestamp and indexed against the
signal id

src/dynalab_core/dlpak.py

@@ -0,0 +1,67 @@
+# Copyright (C) 2026 Hector van der Aa <hector@h3cx.dev>
+# Copyright (C) 2026 Association Exergie <association.exergie@gmail.com>
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+from datetime import datetime, timezone
+from pathlib import Path
+from typing import Literal
+from zipfile import ZIP_DEFLATED, ZipFile
+
+from pydantic import BaseModel, Field
+
+from dynalab_core.buffer import ValueBuffer
+from dynalab_core.errors import DLPakNoDataError
+from dynalab_core.protocols.packets.handshake import SignalDescriptor
+
+
+class RecordManifest(BaseModel):
+    timestamp: datetime = Field(default_factory=lambda: datetime.now(timezone.utc))
+    signals: list[SignalDescriptor] = Field(default_factory=list)
+    comments: str = ""
+
+
+class DLPak:
+    def __init__(self) -> None:
+        self._dir: Path | None = None
+        self._filename: str | None = None
+        self._savetype: Literal["zip", "folder"] = "zip"
+        self._data: ValueBuffer | None = None
+        self._manifest: RecordManifest | None = None
+
+    def set_data(self, data: ValueBuffer) -> None:
+        self._data = data
+
+    def set_manifest(
+        self, timestamp: datetime, all_signals: list[SignalDescriptor]
+    ) -> None:
+        if self._data is None:
+            raise DLPakNoDataError
+
+        data_signal_ids = self._data.get_signal_ids()
+
+        manifest_signals: list[SignalDescriptor] = []
+
+        for signal in all_signals:
+            if signal.id in data_signal_ids:
+                manifest_signals.append(signal)
+
+        self._manifest = RecordManifest(
+            timestamp=timestamp, signals=manifest_signals, comments=""
+        )
+
+    def write(self, dir: str | Path, filename: str) -> None:
+        output_dir = Path(dir)
+
+        if output_dir.is_file():
+            output_dir = output_dir.parent
+
+        file_path = Path(filename)
+
+        if file_path.suffix.lower() != ".dlpak":
+            file_path = file_path.with_suffix(".dlpak")
+
+        output_path = output_dir / file_path
+
+        with ZipFile(output_path, mode="w", compression=ZIP_DEFLATED) as archive:
+            archive.writestr("manifest.json", self._manifest.model_dump_json(indent=2))
+            archive.writestr("data.csv", self._data.export_csv())