Add databricks-serverless-storage-check skill

[GabbysCode]

Summary

Adds databricks-serverless-storage-check — a skill that ships an executable preflight scanner detecting the antipattern where serverless tasks share state through /local_disk0, /tmp, or trustedTemp paths. This is the failure mode behind INTERNAL_ERROR: [Errno 13] Permission denied: '/local_disk0/.../trustedTemp.../...', where a parent task writes to local disk and a child task on a different node cannot read it.

Complementary to the existing databricks-serverless-migration skill (which covers single-notebook migration and correctly recommends /local_disk0/tmp for intra-task scratch). This new skill covers the cross-task case.

Contents

Path	Purpose
skills/databricks-serverless-storage-check/SKILL.md	When-to-use, quick start, output interpretation, the core rule, related skills
skills/databricks-serverless-storage-check/agents/openai.yaml	Codex marketplace metadata (hand-authored)
skills/databricks-serverless-storage-check/scripts/preflight.py	Stdlib-only AST + regex scanner with 5 input modes (--notebook / --dir / --job-yaml / --job-id / --run-id), --json flag, exit codes 0/1/2
skills/databricks-serverless-storage-check/scripts/test_preflight.py	7 self-tests, runs with python3 and no third-party deps
skills/databricks-serverless-storage-check/references/pattern-catalog.md	Full table for FANOUT001–006 + ENV001 with examples, fixes, and the AST/regex rules used
skills/databricks-serverless-storage-check/references/remediation-guide.md	Before/after code for Volumes / Workspace / taskValues / pipeline-downstream handoffs, plus what-not-to-do anti-examples

Detection rules

ID	Severity	Detects
FANOUT001	Blocker	Local-disk path passed to dbutils.notebook.run, taskValues.set, or job-task parameter (resolved through variable assignments and dict/list/tuple literals)
FANOUT002	Blocker	Child notebook (one that uses widgets.get / taskValues.get) reads from a /local_disk0 or /tmp path
FANOUT003	Warning	DAB job with multiple sibling tasks referencing the same local-disk path
FANOUT004	Warning	pipeline_task immediately downstream of a notebook_task that wrote to local temp
FANOUT005	Info	dbutils.fs.cp local-to-local inside a notebook invoked by a multi-task job (heuristic)
FANOUT006	Blocker	Hardcoded BSI signature /local_disk0/spark-*/trustedTemp/... anywhere in source
ENV001	Info	--run-id mode only: routes ENVIRONMENT_SETUP_ERROR.PYTHON_NOTEBOOK_ENVIRONMENT to support escalation (not a fixable pattern)

Sibling cross-reference

Adds one line to skills/databricks-serverless-migration/SKILL.md (Category B: Data Access table) clarifying that /local_disk0/tmp is per-task scratch only and pointing to this skill for cross-task concerns. Flagged here because it touches a sibling skill.

Validation

• python3 scripts/skills.py validate — Everything is up to date.
• python3 skills/databricks-serverless-storage-check/scripts/test_preflight.py — 7/7 passing (BSI repro → blockers + exit 2; DAB sibling-shared /tmp → warning + exit 1; clean /Volumes notebook → 0 findings + exit 0; env-sync regex; BSI signature; exit-code resolution; JSON shape)
• BSI repro fixture (parent writes to /local_disk0/spark-.../trustedTemp-.../..., child reads via widget) triggers FANOUT001 + FANOUT002 + FANOUT006 as blockers
• Scanner has no third-party Python dependencies; databricks CLI is required only for --job-id / --run-id modes

Checklist

• python3 scripts/skills.py validate passes
• SKILL_METADATA entry added in scripts/skills.py
• agents/openai.yaml hand-authored
• Self-tests pass (7/7)
• SKILL.md body under 250 lines (149 lines)
• Frontmatter description includes trigger phrases: trustedTemp, local_disk0, permission denied, fan-out, cross-task
• Signed off per DCO