feat(skills): add mass-operations skill

[didrikhegna]

Adds a mass-operations skill covering Crystallize mass operation files — the JSON batch format executed by the mass-operations runner as a BulkTask.

Sits alongside the existing skills at use-crystallize/skills/mass-operations/, following the same SKILL.md + references/ layout and frontmatter convention.

Contents

File	Covers
SKILL.md	workflow, execution paths, the rules that prevent most failures
references/intents.md	all 59 intents, required fields, _ref outputs, idempotency, where resourceIdentifier is honoured
references/templating.md	_ref chaining, handlebars, defaults.*, upload, the ten fetch* helpers
references/lifecycle.md	CLI and raw API upload/run/monitor, troubleshooting
references/limits.md	every enforced limit — batch caps, string/number bounds, structural rules, and the silent ones

Why it's worth having

Mass operations fail in ways local validation cannot catch, and the published docs are wrong on several points. The skill documents what the runner actually does:

• One invalid operation rejects the entire file. Validation is all-or-nothing, which makes chunking a correctness requirement rather than a nicety.
• An item upsert with neither itemId nor resourceIdentifier always creates — every run. externalReference is not a lookup key. This is the most common source of duplicated catalogue data.
• item/unpublish validates but is not supported by the runner, and fails the whole task rather than one operation.
• A large class of limits fails silently — no error, no log, altered data. Only the first component-type key in a content object is used; null content is coerced to empty and wipes the component; propertiesTable is rebuilt from the shape config; numeric decimalPlaces floors the stored value; choice and selection values not in the config are filtered out.
• max: 0 means "unset" on a files component but rejects everything on images/videos, and required: false disables the configured min entirely — so omitting required is stricter than setting it to false.

It also fixes documentation discrepancies the skill previously inherited: the task lifecycle has no running state, the upsert return-shape guard is legacy 0.0.1 behaviour, resourceIdentifier is unimplemented on several intents that accept it, and shape/piece component settings must be nested under config — the inline form validates and is then silently discarded.

Notes for review

• Guidance is grounded in observed runner behaviour rather than the published docs where the two disagree; the skill says so explicitly and tells the reader to trust the runner.
• Limits are observed values, not contractual API guarantees. The verification line is dated so a reader can judge staleness — worth re-checking when the runner changes.
• Docs-only, no bundled scripts, consistent with the sibling skills.

🤖 Generated with Claude Code

[Plopix]

thx! merged manually