Filter Linear issues by state, assignee, label, priority, dates, and related-object fields using the GraphQL filter argument

Documented steps

1. Pass a `filter` object on any paginated field, e.g. issues(filter: { ... }) — most paginated results support filtering.
2. Use universal comparators eq/neq, in/nin, and case-insensitive eqIgnoreCase/neqIgnoreCase on string/numeric/date fields.
3. Use magnitude comparators lt/lte/gt/gte for numeric and date fields, and string comparators startsWith/endsWith/contains (plus their notX and containsIgnoreCase variants) for text fields.
4. Combine multiple conditions on one filter object for implicit AND; use the `or` key with an array of condition objects for OR logic, e.g. filter: { or: [{ priority: { eq: 4 } }, { priority: { eq: 0 } }] }.
5. Filter on related objects by nesting their fields, e.g. filter: { assignee: { email: { eq: "user@example.com" } } }; for to-many relations use `every` to require all related items match, otherwise any match suffices.
6. For relative date filtering, pass ISO 8601 durations (e.g. "P2W") to date fields to filter relative to the current time instead of a fixed date; use the `null` comparator to filter by presence/absence of an optional field.
7. Official docs: https://linear.app/developers/filtering