feat(device manager): add device dependency resolution

[wakonig]

This PR introduces a dependency resolution for device actions. Dependencies between devices can now be specified through an additional field in the device config: needs. These dependencies will not only sort the initialization but also any subsequent request to multiple devices will respect the sorting.

Please note that needs creates a strong coupling between devices. Disabling a "needed" device will therefore also lead to other devices being invalid. If the device resolution detects a dependency on a disabled device, a warning will be raised.

closes #687

[codecov]

Codecov Report

❌ Patch coverage is 91.20879% with 8 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
.../bec_server/device_server/devices/devicemanager.py	89.06%	3 Missing and 4 partials ⚠️
...ver/device_server/devices/config_update_handler.py	94.11%	0 Missing and 1 partial ⚠️

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[wakonig]

@cappel89 this would be ready for testing if you want.

[Copilot]

Pull request overview

This PR introduces device dependency resolution through a new "needs" field in device configurations. Dependencies are resolved using Kahn's algorithm for topological sorting, ensuring devices are initialized in the correct order and that subsequent device operations respect this ordering.

Key Changes:

• Added "needs" field to device model for specifying dependencies
• Implemented dependency resolution with cyclic dependency detection
• Applied dependency ordering to all device operations (read, stage, trigger, etc.)

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
bec_server/bec_server/device_server/devices/devicemanager.py	Implements dependency resolution algorithm, device ordering map, and get_device_order method
bec_server/bec_server/device_server/devices/config_update_handler.py	Adds update_session_config method and integrates dependency validation into config update flow
bec_server/bec_server/device_server/device_server.py	Applies device ordering to all device operations (trigger, complete, pre_scan, read, stage, unstage)
bec_lib/bec_lib/atlas_models.py	Adds "needs" field to device model with VARIANT hash inclusion
bec_lib/bec_lib/config_helper.py	Documents the new "needs" field with usage examples
bec_server/tests/tests_device_server/test_device_manager_ds.py	Adds comprehensive tests for dependency resolution, cyclic dependency detection, and device ordering
bec_lib/tests/test_device_hashing.py	Updates device hashing tests to include "needs" field in test fixtures and expected outputs

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