feat(configuration): activate workflow with build and flash

[charlesmadjeri]

Issue: Sentience-Robotics/lucy_ros2#105

PR summary

Activate workflow & configure-pipeline

• Dry run then activate: The modal runs ConfigurePipeline with dry_run: true against the TARGET preset (mapping_file = target name) for validation/generate feedback only.
• Wet run on active: After /config/activate promotes the target to active, the workflow starts ConfigurePipeline again with mapping_file: '' (active YAML on disk), dry_run: false, boards_to_flash from the modal, and build_only from BUILD ONLY.
• ACTIVATE ONLY: Skips build/flash entirely after /config/activate and refreshes config/active state.
• Board selection: Empty selection no longer maps to “flash all boards”; it forces ACTIVATE ONLY and guards runActivateWorkflow so build/flash never runs without an explicit board selection when boards exist.
• Mutual exclusion: BUILD ONLY and ACTIVATE ONLY clear each other when one is turned on; switches stay enabled unless the workflow is running (no cross-disabling).

Pipeline / robot metadata (related)

• After a successful flash (non-empty flashed boards), active_meta.yaml records flashed_name / flashed_at; GetConfig returns flashed_config_name / flashed_at for the UI FLASHED tag.