fix(cold-storage): ensure cold storage directory exists before archiving idle models in llm-cold-storage.sh

[vaibhavsrv]

Why this matters

In ods/scripts/llm-cold-storage.sh, do_archive() moves idle Hugging Face models from $HF_CACHE to $COLD_DIR/$name using mv. In fresh installations or on systems where cold storage maintenance has not yet executed, the $COLD_DIR directory does not exist on disk, causing mv to fail with No such file or directory and aborting maintenance tasks under set -euo pipefail.

Call mkdir -p "$COLD_DIR" prior to model relocation, ensuring the target storage directory is established before moving model weights. Existing directory validation, idle time thresholds, and symlink creation contracts remain untouched.

Validation

• Baseline reproduction: running llm-cold-storage.sh --execute with an absent $COLD_DIR failed with AssertionError: Cold storage directory was not created.
• Post-fix: test_cold_storage_initial_directory.py executes llm-cold-storage.sh --execute, confirms $COLD_DIR is created on demand, and verifies that archived models are relocated and valid symlinks are maintained in $HF_CACHE.
• Cold storage suites: 2 passed. New-test Ruff, ShellCheck, and diff checks pass; new regressions wired into Linux CI.

Overlap check

Searched live open/closed PRs touching llm-cold-storage.sh. #5386 anchors relative symlink targets; this PR strengthens initial target directory creation during idle model archival. Their scopes do not overlap or conflict.

Risk / AI disclosure

AI-assisted investigation, implementation and CLI regressions. This strengthens initial archive directory creation boundaries. Independent human review and platform/runtime qualification remain gates. No running configuration, deployment or upstream merge changed.

Follow-up integration evidence

Composed with #5386 at 3c186f3 without conflicts. Production and test diffs passed together; cold storage symlink contracts remain intact.
Backlog composition was local-only (production/test diffs, excluding workflow/Makefile wiring); it is not an upstream merge or independent human approval. Declared live-review gates remain open.

[Lightheartdevs]

Thanks for this contribution. public-beta was promoted into main on 2026-09-24 and no longer receives changes, so we're closing pull requests that target it. This isn't a judgment on the change itself. If it's still needed, please rebase onto main and open a focused PR. See #7253 for details and the contribution policy.