Add a SmartCrop control to the new Angular image editor

[oidacra]

Description

The new Angular image editor (@dotcms/image-editor, built in #36063 / PR #36236) supports manual crop with aspect presets and orientation, but does not yet expose dotCMS's content-aware SmartCrop filter, which auto-crops an image to a target size by selecting the most relevant region.

Add a SmartCrop control to the editor. Like the rest of the editor, this is a server-side "viewer of the endpoint": the control builds a /contentAsset/image/... filter URL and the server renders it (no client-side pixel work).

Backend contract (already implemented — libvips-only)

The smartcrop filter is registered in com.dotmarketing.image.vips.VipsImageFilterApiImpl (.put("smartcrop", VipsSmartCropImageFilter.class)). It requires DOT_IMAGE_API_USE_LIBVIPS=true (no legacy fallback — same constraint as AVIF and the libvips Rotate filter).

URL form:

/contentAsset/image/{id}/{field}/filter/smartcrop/smartcrop_w/{w}/smartcrop_h/{h}/smartcrop_mode/{mode}

mode is one of attention | entropy | centre. Verified on stage (falconteam-image-editor.dotcms.dev):

• .../filter/smartcrop/smartcrop_w/500/smartcrop_h/400/smartcrop_mode/attention
• .../filter/smartcrop/smartcrop_w/500/smartcrop_h/400/smartcrop_mode/entropy
• .../filter/smartcrop/smartcrop_w/500/smartcrop_h/400/smartcrop_mode/centre

Mode	Picks the region by
attention	Saliency — visually important areas (default)
entropy	Detail / busyness
centre	Geometric centre

Surfacing

The exact placement — a mode inside the existing Crop tool vs a separate toolbar control — is deferred to the provided design. The acceptance criteria below are behavior-focused, not layout-specific.

Acceptance Criteria

• The editor exposes a SmartCrop control that accepts a target width and height in pixels.
• The control offers all three modes — attention, entropy, centre — defaulting to attention.
• Selecting SmartCrop with width W, height H, mode M renders a live preview built from …/filter/smartcrop/smartcrop_w/W/smartcrop_h/H/smartcrop_mode/M, like every other edit.
• Switching the mode with the same W×H re-renders the preview using the new mode.
• SmartCrop is mutually exclusive with manual Crop and the Resize/output-dimensions: applying SmartCrop clears/overrides them (it already yields the final W×H), mirroring the existing Resize-removes-Crop rule in the URL builder.
• The applied SmartCrop appears in the edit history (applied-edits list) and can be removed/undone like other edits.
• Width/height reject non-positive values (min 1); no filter URL is emitted for an incomplete entry (missing W or H).
• The SmartCrop filter is reflected in the preview address bar / copy-URL like other filters.
• Unit tests cover the URL-builder branch (each mode → expected params; mutual exclusion with crop/resize) and the control's dispatch.

Priority

Medium

Additional Context

• Builds on the new Angular image editor: [IMAGE EDITOR] Build DotImageEditorComponent modal shell and image-editor signalStore #36063 (PR feat(image-editor): add Angular image editor #36236); part of the Edit Content screen redesign epic Edit Content Screen — GTM #35846.
• libvips dependency: SmartCrop only renders where DOT_IMAGE_API_USE_LIBVIPS=true (no legacy fallback). Where libvips is disabled the preview will error; detecting that from the frontend is out of scope here (a follow-up could hide/disable SmartCrop via a capability flag).
• The design for the control will be provided separately.
• Related follow-ups discussed alongside this: a focal/focus-point picker (separate issue) and the Save-to-content (new rendition) flow (separate issue).