style: format frontend, docs and skills with prettier; add .prettierignore

One-time prettier --write so the new format:check CI gate starts green.
.prettierignore excludes generated (api-client.ts, documentation.json),
vendored (public/cibg-huisstijl), and backend (dotnet format owns it).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/app/brief/domain/brief.machine.ts

@@ -1,5 +1,13 @@
 import { assertNever } from '@shared/kernel/fp';
-import { Brief, BriefStatus, LetterBlock, LetterSection, LibraryPassage, allBlocks, canSubmit } from './brief';
+import {
+  Brief,
+  BriefStatus,
+  LetterBlock,
+  LetterSection,
+  LibraryPassage,
+  allBlocks,
+  canSubmit,
+} from './brief';
 import { RichTextBlock, deepCopyBlock, emptyBlock } from '@shared/kernel/rich-text';
 
 /**
@@ -59,8 +67,15 @@ function nextLocalIndex(brief: Brief): number {
   return max + 1;
 }
 
-function mapSection(brief: Brief, sectionKey: string, f: (s: LetterSection) => LetterSection): Brief {
-  return { ...brief, sections: brief.sections.map((s) => (s.sectionKey === sectionKey ? f(s) : s)) };
+function mapSection(
+  brief: Brief,
+  sectionKey: string,
+  f: (s: LetterSection) => LetterSection,
+): Brief {
+  return {
+    ...brief,
+    sections: brief.sections.map((s) => (s.sectionKey === sectionKey ? f(s) : s)),
+  };
 }
 
 /** The section a block currently lives in, or undefined if the block is gone. */
@@ -86,7 +101,11 @@ function withEdit(s: BriefState, f: (b: Brief) => Brief): BriefState {
   return { ...s, brief };
 }
 
-function insertPassages(brief: Brief, sectionKey: string, passages: readonly LibraryPassage[]): Brief {
+function insertPassages(
+  brief: Brief,
+  sectionKey: string,
+  passages: readonly LibraryPassage[],
+): Brief {
   let idx = nextLocalIndex(brief);
   // The freeze happens HERE: each block gets a deep VALUE copy of the library content,
   // so later library edits can never mutate this letter (frozen snapshot).
@@ -102,7 +121,11 @@ function insertPassages(brief: Brief, sectionKey: string, passages: readonly Lib
 }
 
 function addFreeText(brief: Brief, sectionKey: string): Brief {
-  const block: LetterBlock = { type: 'freeText', blockId: `local-${nextLocalIndex(brief)}`, content: emptyBlock() };
+  const block: LetterBlock = {
+    type: 'freeText',
+    blockId: `local-${nextLocalIndex(brief)}`,
+    content: emptyBlock(),
+  };
   return mapSection(brief, sectionKey, (s) => ({ ...s, blocks: [...s.blocks, block] }));
 }
 
@@ -118,7 +141,11 @@ function editBlockContent(brief: Brief, blockId: string, content: RichTextBlock)
   );
 }
 
-function moveWithinSection(blocks: readonly LetterBlock[], blockId: string, toIndex: number): LetterBlock[] {
+function moveWithinSection(
+  blocks: readonly LetterBlock[],
+  blockId: string,
+  toIndex: number,
+): LetterBlock[] {
   const from = blocks.findIndex((b) => b.blockId === blockId);
   if (from === -1) return [...blocks];
   const clamped = Math.max(0, Math.min(toIndex, blocks.length - 1));
@@ -140,12 +167,18 @@ export function reduce(s: BriefState, m: BriefMsg): BriefState {
     // Section-level guard (defense-in-depth): locked sections never accept edits, even if a
     // Msg reaches the reducer. The UI already hides controls for locked sections.
     case 'PassagesInserted':
-      return withEdit(s, (b) => (isSectionEditable(b, m.sectionKey) ? insertPassages(b, m.sectionKey, m.passages) : b));
+      return withEdit(s, (b) =>
+        isSectionEditable(b, m.sectionKey) ? insertPassages(b, m.sectionKey, m.passages) : b,
+      );
     case 'FreeTextBlockAdded':
-      return withEdit(s, (b) => (isSectionEditable(b, m.sectionKey) ? addFreeText(b, m.sectionKey) : b));
+      return withEdit(s, (b) =>
+        isSectionEditable(b, m.sectionKey) ? addFreeText(b, m.sectionKey) : b,
+      );
     case 'BlockContentEdited':
       return withEdit(s, (b) =>
-        isSectionEditable(b, sectionKeyOfBlock(b, m.blockId)) ? editBlockContent(b, m.blockId, m.content) : b,
+        isSectionEditable(b, sectionKeyOfBlock(b, m.blockId))
+          ? editBlockContent(b, m.blockId, m.content)
+          : b,
       );
     case 'BlockRemoved':
       return withEdit(s, (b) =>
@@ -157,18 +190,34 @@ export function reduce(s: BriefState, m: BriefMsg): BriefState {
       return withEdit(s, (b) =>
         isSectionEditable(b, sectionKeyOfBlock(b, m.blockId))
           ? mapBlocks(b, (blocks) =>
-              blocks.some((x) => x.blockId === m.blockId) ? moveWithinSection(blocks, m.blockId, m.toIndex) : [...blocks],
+              blocks.some((x) => x.blockId === m.blockId)
+                ? moveWithinSection(blocks, m.blockId, m.toIndex)
+                : [...blocks],
             )
           : b,
       );
 
     case 'Submitted':
       // Guard the transition AND the completeness invariant.
-      return transition(s, 'draft', () => ({ tag: 'submitted', submittedBy: m.by, submittedAt: m.at }), canSubmit);
+      return transition(
+        s,
+        'draft',
+        () => ({ tag: 'submitted', submittedBy: m.by, submittedAt: m.at }),
+        canSubmit,
+      );
     case 'Approved':
-      return transition(s, 'submitted', () => ({ tag: 'approved', approvedBy: m.by, approvedAt: m.at }));
+      return transition(s, 'submitted', () => ({
+        tag: 'approved',
+        approvedBy: m.by,
+        approvedAt: m.at,
+      }));
     case 'Rejected':
-      return transition(s, 'submitted', () => ({ tag: 'rejected', rejectedBy: m.by, rejectedAt: m.at, comments: m.comments }));
+      return transition(s, 'submitted', () => ({
+        tag: 'rejected',
+        rejectedBy: m.by,
+        rejectedAt: m.at,
+        comments: m.comments,
+      }));
     case 'Sent':
       return transition(s, 'approved', () => ({ tag: 'sent', sentAt: m.at }));