[pournasserian]

Closes #2605

What

The first slice of F-FRM (#2426): generated create and edit forms for content types, with a widget per built-in field type through FormField (FRM-01). A save is a person's operation in a change set (FRM-02), which goes through checks and review like an agent's.

• Core (FluentCMS.Core.Content): IEntryEdits.SaveAsync(EntryEdit).
  • It writes the version, then opens a change set with the person's rationale and sources and adds the operation, all in one unit of work, as ProposedEntryWrite does for agents. A refused set or field rolls the version back, so no version exists outside a set (AUD-N1).
  • An update is based on the published version, and a draft never published is a create of its next version.
  • The set stays open, and the person submits it from the set view (Show the check run on the set view and submit an open set #2603).
• Admin:
  • /content lists the content types, and /content/{slug} lists a type's entries, newest first, with state and versions. Both lists rove.
  • /content/{slug}/new and /content/{slug}/{id} render the type's latest definition, one FieldWidget per field. Each widget is in a FormField with the field's description, a required mark and its error:
    • text: input with maxlength
    • richText: textarea
    • number: number input
    • boolean: checkbox
    • dateTime: datetime-local in UTC, or a date input for dateOnly
    • enum: select of its values
    • reference: select of the target type's entries
    • media: select of the library's assets
    • list and json: JSON textarea
  • FieldValues turns each posted text into the field's JSON value, and a stored value back into what the widget shows. Each value is checked with FieldTypeRegistry.ValidateValue before the save, and a required field left empty is reported. Each problem shows next to its field, and the typed values stay.
  • The directory checks the document again on save, and its "Field 'x': ..." errors go to their fields.
  • An edit posts the version it read. A form from an older version is refused, and the entry is shown as it is now.
  • A save lands on the new set with a note saying to submit it. The header gets a Content link.
  • Entity types are listed, with a note that their form, with fact metadata, is the next slice.
• Accessibility: the axe check covers /content, a type's entries and the new-entry form.

Why

• A Core service for the save. The form needs the same version-plus-operation unit of work an agent's write uses. P1 keeps that logic out of the screen, and a later tool for people's edits can call the same service.
• One set per save, left open. A person may want several edits reviewed together, but joining an existing open set needs a picker and the CHG-07 rules. That comes with edit-in-place. Leaving the set open lets the person look at the diff before submitting.
• Selects for references and media for now. The epic's pickers need search (Add the search index on PostgreSQL and SQLite and the search tool #2566 just landed). A select of every candidate works at M1 scale until the next slice.
• UTC for date and time. The browser's date-time input has no offset, and the stored value needs one. The form says the time is UTC rather than guessing the person's zone.
• Not in this PR: entity forms (next slice), search-backed pickers, rule hints per field (FRM-03, needs F-RUL F-RUL: Rule book as versioned content #2419), and editing inside an existing set (CHG-07).

Tests

Unit and bUnit (GeneratedFormTests):

• Every built-in type turns its posted text into the right JSON value. A bad number, time, date or JSON is a problem, and an empty field has no value.
• Stored values show as their widgets take them: a UTC date-time from any offset, booleans, numbers as stored, and indented JSON with non-Latin text unescaped.
• Each type renders its widget with the field's name, label link, required mark and error, and an enum marks the stored value.

Integration:

• EntryEditsTests on SQLite and PostgreSQL:
  • A save opens an open set with the person as initiator, the rationale, the sources and the create.
  • An edit of a draft is a create of version 2 in a new set, and a stale base version is refused.
  • A blank rationale or an invalid field stores neither the version nor a set.
• EntryFormScreenTests against the host:
  • A person creates an entry with a field of every type and lands on the open set. The set holds the create with the sources split by line, and every value is stored as typed.
  • The edit form shows the stored values, and its save opens a second set with version 2.
  • Bad values and missing fields are reported next to their fields, and nothing is stored.
  • A stale form shows the entry as it is now.
  • The content pages list types and entries, need sign-in, and answer 404 for an unknown type or entry.

dotnet build -warnaserror and the full suite with the browser tests pass locally against a postgres:17 container as well as SQLite. One run on a loaded machine had seven PostgreSQL failures in untouched classes and one in the keyboard browser test; all 65 tests of those classes passed on a rerun. No new package and no new project reference.

Checklist

• Linked to an issue a maintainer has confirmed
• Targets v2
• Tests or docs updated where behaviour changed
• No tool-generated co-author trailers or footers