docs(16.2): amend D-10 to strip on every admin save, categories included

.planning/notes/journal-html-sanitizing-bluemonday.md

@@ -29,6 +29,8 @@ Everything else that UGC refuses is refused: `script`, `style`, `iframe`, `objec
 - **Byte-stable when nothing is stripped.** `sanitizeHTML` returns the goldmark output unchanged when that output and bluemonday's output tokenize to the same tokens: the same type, tag name, decoded text and set of decoded attributes. Otherwise it returns bluemonday's output. bluemonday re-escapes `"` as `"` and `'` as `'`, so storing its output every time would rewrite every imported post on its next save. Returning the original bytes is safe only on that token-level equality. Any element, attribute or comment that the policy drops makes the tokens differ, and then the sanitized output is stored.
 - **Category content refuses.** `classes.CheckHTML` keeps its exported signature and its 422 contract. D-21 stores category content exactly as submitted, and `TestCategoriesAdminContent` asserts a 422 for unsafe content. CheckHTML now uses the same policy and comparison, and refuses whenever the policy would change the HTML.
 
+- **Amended 2026-10-10 (Phase 16.2 D-10): category content strips too, and admin saves report what was stripped.** The user chose one rule for both: post and category admin writes store the sanitized output and never fail. `CheckHTML`'s 422 contract for categories and the `TestCategoriesAdminContent` 422 assertion are retired in Phase 16.2. Winter stored category content unsanitized; that was a gap, not a contract. When the policy removes anything, the admin save response names what was removed. The policy (and the layer's sanitize-html mirror) is extended only for the Blog Editor's own output, such as the `figure data-embed`/`data-id` embed placeholder.
+
 - **Translations follow the same rule (2026-10-10, audit W-1).** `classes.FormatTranslation` runs on every locale of every API and import write: a non-blank `content` re-derives `content_html` with `FormatHTML` (a supplied `content_html` is replaced, as for the host column); a `content_html` sent alone goes through `classes.SanitizeHTML`, the same policy. A translation keyed on the default locale, which `translate.SetTranslated` writes straight into the host column, is covered too. PHP stored a client-supplied translated `content_html` as-is on the API and import paths; the port follows the PHP admin widget, which always derived it.
 - **Duplicate attributes count as a change (audit W-2).** `golang.org/x/net/html` drops a repeated attribute while tokenizing, so the byte-stable comparison could not see `href="https://x" href="javascript:..."`. `htmlTokens` compares the raw attribute names of each start tag (`rawAttrNames`) with the attributes the tokenizer kept; any difference stores the sanitized output and makes `CheckHTML` refuse.
 

.planning/phases/16.2-plugin-provided-field-types-and-the-blog-editor-formwidget/16.2-CONTEXT.md

@@ -21,17 +21,17 @@ Out of scope: a core cabana `richeditor` type, a media library browser, and HTML
 
 ### Blog Editor: what it is
 - **D-01:** The Blog Editor is a **WYSIWYG HTML editor with a source (raw HTML) toggle**, built on ProseMirror through TipTap. It is not a block editor and not a markdown editor.
-- **D-02:** **An admin save stores HTML in both columns.** `content` holds the edited HTML and `content_html` holds the same HTML after it passes `classes.CheckHTML`. The API response shape is unchanged; `content` is simply HTML, as the PHP export already carries for imported posts. — **Reversibility:** costly — every post saved from the admin becomes HTML-content. A later move back to markdown would need an HTML-to-markdown migration across live posts.
+- **D-02:** **An admin save stores HTML in both columns.** `content` holds the edited HTML and `content_html` holds the same HTML after the sanitizer (D-10); both columns store the sanitized HTML. The API response shape is unchanged; `content` is simply HTML, as the PHP export already carries for imported posts. — **Reversibility:** costly — every post saved from the admin becomes HTML-content. A later move back to markdown would need an HTML-to-markdown migration across live posts.
 - **D-03:** **Byte-preserving unless edited.** If the post body is not touched in the editor, the save writes back exactly the stored HTML; the editor must not re-serialize an untouched document. Once the body is edited in WYSIWYG, markup the schema doesn't know (custom classes, divs, attributes) is kept as far as possible through generic node and attribute preservation. The source tab always edits the exact HTML.
-- **D-04:** v1 features: basic text (headings, bold/italic, lists, links, blockquote), **images**, **tables**, and **embeds plus a raw HTML block**. The raw HTML block is still subject to `CheckHTML`.
-- **D-05:** **Embeds are an allowlisted placeholder node**, for example `<figure data-embed="youtube" data-id="…">`, that passes `CheckHTML` unchanged. **The XSS gate is not relaxed to allow iframes.** The frontend expands the placeholder into the real iframe (D-17). — **Reversibility:** costly — the placeholder markup becomes stored content in live posts, and the layer's renderer depends on it.
+- **D-04:** v1 features: basic text (headings, bold/italic, lists, links, blockquote), **images**, **tables**, and **embeds plus a raw HTML block**. The raw HTML block is still subject to the sanitizer (D-10).
+- **D-05:** **Embeds are an allowlisted placeholder node**, for example `<figure data-embed="youtube" data-id="…">`, that passes the bluemonday policy (and the layer's sanitize-html policy) byte for byte; both policies are extended for exactly the editor's own output (`figure` `data-embed`/`data-id`, and any image or table attributes the editor emits), pinned by a test. **The XSS gate is not relaxed to allow iframes.** The frontend expands the placeholder into the real iframe (D-17). — **Reversibility:** costly — the placeholder markup becomes stored content in live posts, and the layer's renderer depends on it.
 - **D-06:** The editor is **translatable like today's `mlmarkdown`**: a locale switcher over a locale → HTML map, stored through the translate overlay.
 
 ### Markdown vs HTML posts
 - **D-07:** **A markdown post opens with its `content_html`**, and the next admin save stores HTML (D-02). This is a one-way migration on first edit, with **no per-post format flag** and no new column.
 - **D-08:** **The Blog Editor replaces `mlmarkdown` for Journal post `content`** in `models/post/fields.yaml`. `markdown` and `mlmarkdown` stay cabana core types for other plugins. The `excerpt` field is unchanged.
 - **D-09:** **The public write API is unchanged.** `POST`/`PUT /_journal/api/v1/posts` keep the PHP contract: `content` is markdown and the server renders `content_html` with `FormatHTML`. Only the admin form path stores HTML.
-- **D-10:** **Admin save gate: `CheckHTML` refuses, nothing is sanitized.** Unsafe HTML returns a 422 with a field error, as category content does today, and nothing is silently rewritten. No sanitizer dependency is added. `CheckHTML` must run on every admin write path for both the default and the non-default locale values. The admin save path must stop running `FormatHTML`/goldmark over HTML content, which is the current data-loss bug (todo `journal-imported-html-admin-resave.md`).
+- **D-10 (amended 2026-10-10, supersedes the original refuse-only gate):** **Admin save gate: strip, never refuse.** Every admin write of post and category content (default and non-default locale) stores the output of the shared bluemonday policy (`classes.SanitizeHTML`, decision note `journal-html-sanitizing-bluemonday.md`), which returns the bytes unchanged when nothing is stripped. A save never fails because of unsafe markup. When the policy removed anything, the save response tells the admin what was removed (for example "2 elements were removed: style, iframe") and the form reloads the stored value; a save that removed nothing keeps today's response shape. The admin save path must stop running `FormatHTML`/goldmark over HTML content, which is the current data-loss bug (todo `journal-imported-html-admin-resave.md`). — *Original text: "`CheckHTML` refuses, nothing is sanitized … No sanitizer dependency is added." Superseded because 16.1 adopted bluemonday and the user chose strip (WordPress/Winter-post behaviour) so an edit never fails on legacy blocks the author did not touch.*
 
 ### Field type contract (framework)
 - **D-11:** **Plugins register field types under a short global alias**, for example `type: blogeditor`. Boot fails loudly if two plugins, or a plugin and a cabana core type, claim the same alias. This is closer to Winter's `registerFormWidgets` aliases than to a namespaced key. — **Reversibility:** costly — aliases end up in plugin `fields.yaml` files across repos; renaming means editing every consumer.
@@ -50,7 +50,7 @@ Out of scope: a core cabana `richeditor` type, a media library browser, and HTML
 - **D-16:** **The editor library is TipTap (ProseMirror, MIT).** It is wrapped in a plain custom element and bundled in **sm-journal-plugin's own JS build** (`assets/src` → `assets/dist`), with the bundle committed and embedded, like the admin SPA `dist/`. The host app needs no npm. The admin SPA itself gains no editor dependency.
 - **D-17:** **Embeds render in the `vue-journal-layer` blog views.** The layer expands allowlisted embed placeholders into privacy-friendly iframes (for example `youtube-nocookie.com`), so grzybyfunkcjonalne.pl shows them. A new layer tag is pinned in `vue-grzybyfunkcjonalne-app`.
 - **D-18:** **Images are uploaded through the existing backend-authenticated Journal media upload route**, by drag-and-drop or file picker. The editor inserts `<img src>` with alt text and an optional caption (`figure`/`figcaption`). There is no media library browser.
-- **D-19:** **Journal category content uses the Blog Editor** (`blogeditor`, or `mlblogeditor` if the category content attribute is translatable in the PHP tree) instead of the textarea. **No core cabana `richeditor` type** is added. This closes todo `cabana-richeditor-field-type.md` inside Journal. The existing `CheckHTML` gate in the Categories controller's `FormBeforeCreate`/`FormBeforeUpdate` stays.
+- **D-19:** **Journal category content uses the Blog Editor** (`blogeditor`, or `mlblogeditor` if the category content attribute is translatable in the PHP tree) instead of the textarea. **No core cabana `richeditor` type** is added. This closes todo `cabana-richeditor-field-type.md` inside Journal. Category content follows D-10 (amended): it is stripped like posts, not refused. This replaces the 422 `CheckHTML` gate in the Categories controller's `FormBeforeCreate`/`FormBeforeUpdate` (Winter stored category content unsanitized; that was a gap, not a contract to keep).
 
 ### Claude's Discretion
 - The exact `pact` interface name and method set, Go identifiers, the element value/event contract details, and the asset declaration shape, all within D-11 to D-15.