[Feature]: Add richer field types and validation to plugin resources

[jacoplane]

Problem

Plugin resource fields currently support only:

• text
• longtext
• number
• date
• boolean

This makes it difficult for plugin authors to create structured admin forms using host-owned resource pages. Values such as date-times, URLs, media references, and tags must currently be encoded as loosely formatted text.

Some plugins also need structured or repeatable values. For example, an event series may contain recurrence settings and per-occurrence exceptions. Encoding these as text weakens validation, while separate custom admin forms require editor.code.

The alternative is to build a custom admin app, which requires editor.code and runs unsandboxed in the admin window.

Proposed solution

Extend resources[].fields with additional declarative field types and metadata, including:

• dateTime, preferably with timezone support
• url and email
• media or image
• select, multiSelect, or tags
• default values
• descriptions, help text, and placeholders
• validation constraints such as min/max, pattern, and URL validation
• validated structured values, such as JSON objects/arrays or repeatable field groups

The same schema should ideally be enforced by both the host-provided admin UI and the plugin storage/API boundary.

Aligning this with the existing CMS content field types where practical would reduce duplication and make the plugin SDK easier to learn.

Alternatives considered

Plugins can store structured values as text or request editor.code and implement their own admin UI. These approaches either reduce data quality or require a higher-trust permission than should be necessary for ordinary resource management.

Area

Plugins