feat(backup): add user asset backup & migration module

src/copaw/app/crons/backup_job.py

@@ -0,0 +1,65 @@
+# -*- coding: utf-8 -*-
+"""Helper to build a CronJobSpec for the daily backup task."""
+from __future__ import annotations
+
+from .models import (
+    CronJobRequest,
+    CronJobSpec,
+    DispatchSpec,
+    DispatchTarget,
+    JobRuntimeSpec,
+    ScheduleSpec,
+)
+
+BACKUP_JOB_ID = "_backup"
+BACKUP_JOB_NAME = "Daily Asset Backup"
+
+
+def build_backup_cron_job(
+    *,
+    schedule: str = "0 2 * * *",
+    user_id: str = "system",
+    session_id: str = "backup",
+    channel: str = "internal",
+    timezone: str = "UTC",
+    timeout_seconds: int = 300,
+) -> CronJobSpec:
+    """Create a :class:`CronJobSpec` for the daily asset backup task.
+
+    Parameters
+    ----------
+    schedule:
+        Cron expression (5-field). Defaults to ``"0 2 * * *"`` (02:00 daily).
+    user_id / session_id:
+        Dispatch target identifiers.
+    channel:
+        Dispatch channel name.
+    timezone:
+        Timezone for the cron schedule.
+    timeout_seconds:
+        Maximum execution time for a single backup run.
+    """
+    return CronJobSpec(
+        id=BACKUP_JOB_ID,
+        name=BACKUP_JOB_NAME,
+        enabled=True,
+        schedule=ScheduleSpec(cron=schedule, timezone=timezone),
+        task_type="agent",
+        request=CronJobRequest(
+            input="Run daily asset backup",
+            user_id=user_id,
+            session_id=session_id,
+        ),
+        dispatch=DispatchSpec(
+            channel=channel,
+            target=DispatchTarget(
+                user_id=user_id,
+                session_id=session_id,
+            ),
+        ),
+        runtime=JobRuntimeSpec(
+            max_concurrency=1,
+            timeout_seconds=timeout_seconds,
+        ),
+        meta={"source": "backup_scheduler"},
+    )

src/copaw/app/workspace/service_factories.py

@@ -168,3 +168,40 @@ def mcp_config_loader():
     ws._service_manager.services["mcp_config_watcher"] = watcher
     return watcher
     # pylint: enable=protected-access
+
+
+async def create_backup_service(ws: "Workspace", _):
+    """Create backup-related services.
+
+    Creates AssetExporter, AssetImporter, BackupScheduler.
+
+    Args:
+        ws: Workspace instance
+        _: Unused service parameter
+
+    Returns:
+        dict with exporter, importer, and scheduler instances
+    """
+    from ...backup.exporter import AssetExporter
+    from ...backup.importer import AssetImporter
+    from ...backup.scheduler import BackupScheduler
+
+    # Try to get memory manager for consistent memory snapshots
+    memory_manager = ws._service_manager.services.get(
+        "memory_manager",
+    )  # pylint: disable=protected-access
+
+    exporter = AssetExporter(memory_manager=memory_manager)
+    importer = AssetImporter(workspace_dir=ws.workspace_dir)
+    scheduler = BackupScheduler(exporter=exporter)
+
+    services = {
+        "asset_exporter": exporter,
+        "asset_importer": importer,
+        "backup_scheduler": scheduler,
+    }
+    ws._service_manager.services.update(
+        services,
+    )  # pylint: disable=protected-access
+    logger.info("Backup services registered for agent: %s", ws.agent_id)
+    return services

src/copaw/backup/__init__.py

@@ -0,0 +1,2 @@
+# -*- coding: utf-8 -*-
+"""CoPaw user asset backup & migration module."""

src/copaw/backup/errors.py

@@ -0,0 +1,22 @@
+# -*- coding: utf-8 -*-
+"""Custom exceptions for user asset backup & migration."""
+from __future__ import annotations
+
+
+class InvalidAssetPackageError(Exception):
+    """Raised when a ZIP asset package is invalid or corrupted.
+
+    Examples: missing manifest.json, malformed JSON, checksum mismatch.
+    """
+
+
+class IncompatibleVersionError(Exception):
+    """Raised when the asset package schema version is incompatible.
+
+    This happens when the package's major version is higher than the
+    current system version, or when a required migration path is missing.
+    """
+
+
+class InsufficientStorageError(Exception):
+    """Raised when there is not enough disk space for backup or import."""