WIP feat: wire cluster autodiscovery into SlurmConfig and CLI

[gregorweiss]

Connects the autodiscovery module to existing infrastructure so users benefit from it without changing their workflow.

• Add SlurmConfig.from_cluster() classmethod that auto-populates account/partition from discovered cluster info
• Add mdfactory config cluster CLI command to display discovered SLURM resources
• Add mdfactory config cluster --json for machine-readable output
• Update analysis run --slurm and analysis artifacts run --slurm to use autodiscovery when --account not provided

Files Changed

File	Change
mdfactory/analysis/submit.py	Add SlurmConfig.from_cluster() classmethod
mdfactory/cli.py	Add config cluster command, autodiscovery fallback in SLURM commands
mdfactory/tests/test_submit.py	Tests for from_cluster()
mdfactory/tests/test_cli_cluster.py	Tests for config cluster command

Test plan

• pytest mdfactory/tests/test_submit.py -v — all pass
• pytest mdfactory/tests/test_cli_cluster.py -v — all pass
• Manual: mdfactory config cluster on SLURM node shows cluster info
• Manual: mdfactory config cluster on laptop shows graceful message