a3c6f54ad3
Add the ability to filter issues by custom field values throughout
the entire search stack:
- DB: applyCustomFieldCondition joins custom_field_value with AND
semantics (all specified fields must match)
- Indexer: CustomFieldFilters map passed through SearchOptions and
ToDBOptions
- Web: parse cf_{fieldID}={value} query params, show dropdown
filters in the issue list sidebar for org-level fields
- API: both SearchIssues and ListIssues accept cf_ query params
Closes #496
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>