Working draft / WIP — needs a deep code review. (but generally it's working) :-D

Summary of Changes

— Add frontend category editing to com_content (controller/model/view/template, routing, icon layouts) to mirror the long-existing frontend article editing.
— Introduce core.edit.frontend for categories and show the edit icon on category pages when authorized.
— Reuse the admin category form (title/alias, description, image, custom fields, publishing/state, metadata, tags, associations, permissions) and hide the unused workflow tab on the frontend.
— Force category edit links to use the edit layout and numeric-only routes (ID retained under SEF); carry Itemid and rebuild breadcrumbs to keep menu context.
— Frontend article editing has worked for years; categories were the missing piece—this PR aims to close that gap.

Testing Instructions

1. Ensure a user has core.edit.frontend plus core.edit/core.edit.own (and core.edit.state if needed) on the target category/branch.
2. On the frontend, open a com_content category page; confirm the edit icon appears when authorised.
3. Click the icon → category edit form loads (layout=edit); verify page title/heading uses the category title and breadcrumbs stay in context.
4. Edit fields (title/alias, description, image, tags, metadata, custom fields, associations, permissions) and save/apply; confirm the category updates and routes back with the correct Itemid.
5. With a user lacking core.edit.frontend, confirm the icon is hidden and direct access to the edit route is rejected (403).
6. Multilingual: with associations enabled, open a category in a non-default language, edit, and confirm associations persist.
7. Verify trashed categories do not show the edit icon; unpublished categories use the “eye-slash” icon.

Actual result BEFORE applying this Pull Request

— Frontend article editing works, but frontend category editing is missing: no edit icon, no frontend form, and categories must be edited in the administrator.

Expected result AFTER applying this Pull Request

— Authorised users can edit categories on the frontend via the new icon; the form mirrors backend fields, respects ACL, preserves Itemid/breadcrumb context, and routes with numeric IDs.