Fix the two checks the full run 304 found red

The full CI run on 4c7861b had two red checks. Neither showed when
only the touched modules ran, because each needs a module before it.

- e2e 40c-iii (#347): a stroke on a tilemap drew the captions
  "Comment" and "Held" again. They are a note and a group that e2e 36
  leaves in a graph. AnnotationView gave its caption a new TextStyle
  on every redraw, and Pixi draws a text again for a new style. The
  graph redraws on every edit of the project. The caption now keeps
  its style while colour and width stay the same.
- e2e 49a: a plain user deleting a shared file got 404 instead of
  403. Since #344 the DELETE route asked whether the file exists
  before whose it is. It now refuses a stranger first, so another
  folder tells them nothing. The wiki's API page says so.

Tests:
- Unit annotation-view (new): 2 green, counter-check 1 red
- e2e 36,39,40,49 (melektaus-atx): both checks green, 49 then hit a
  harness timeout (CDP Network.enable) once
- e2e 49 alone (melektaus-atx): ALL PASSED - 22 checks
- Gate (melektaus-atx): CHECK EXIT 0, 261 files, 4040 tests

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

api/index.php

@@ -532,13 +532,14 @@ function routeFiles(
 
     if ($method === 'DELETE') {
         $file = implode('/', array_slice($parts, 1));
-        if (!$store->exists($file)) {
-            Response::error("{$noun} not found", 404);
-        }
+        // Asked before whether there is one: somebody else's folder tells a stranger nothing.
         $folder = HashedFileStore::folderOf($file);
         if (!$isAdmin && ($folder === '' || $folder !== $users->folderOf($user))) {
             Response::error('Only its owner may delete this file', 403);
         }
+        if (!$store->exists($file)) {
+            Response::error("{$noun} not found", 404);
+        }
         $uses = (new FileUsage(dirname(__DIR__) . '/data'))->of($file);
         if ($uses !== []) {
             Response::error(FileUsage::refusal($uses, $user, $isAdmin), 409);

src/editor/graph/AnnotationView.ts

@@ -18,6 +18,8 @@ const PAD = 8;
 export class AnnotationView extends Widget {
   private readonly box = new Graphics();
   private readonly caption: Text;
+  /** Colour and width of the caption's style, see `redraw`. */
+  private styleKey = '';
   selected = false;
 
   constructor(
@@ -105,7 +107,13 @@ export class AnnotationView extends Widget {
       .lineTo(this.w - 2, this.h - RESIZE_HANDLE / 2)
       .stroke({ width: 1, color: text, alpha: 0.5 });
 
+    // A new style draws the caption again even when nothing changed, and the graph redraws on every
+    // edit of the project, a stroke on a tilemap included (#347). So only a new colour or width sets one.
+    const styleKey = `${text}|${this.w}`;
+    if (styleKey !== this.styleKey) {
+      this.styleKey = styleKey;
       this.caption.style = this.captionStyle(text);
+    }
     this.caption.text =
       this.kind === 'group'
         ? truncate(this.annotation.text, this.caption.style, Math.max(this.w - PAD * 2, 1))

tests/editor/annotation-view.test.ts

@@ -0,0 +1,35 @@
+/**
+ * A graph draws its groups and comments again on every edit of the project, a stroke on a tilemap
+ * included. A caption that is given a new style is drawn again as text, so it keeps its style for as
+ * long as colour and width stay the same (#347).
+ */
+import type { Text } from 'pixi.js';
+import { describe, expect, it } from 'vitest';
+import { AnnotationView } from '../../src/editor/graph/AnnotationView';
+
+const note = { id: 'n1', x: 0, y: 0, w: 200, h: 120, text: 'Comment' };
+const captionOf = (view: AnnotationView) => view.children[1] as Text;
+
+describe('the caption of a group or comment', () => {
+  // A comment only: a group's title is cut to its width by measuring it, which needs a canvas. The
+  // groups are seen in the browser, in e2e 40c-iii.
+  it('keeps its style through a redraw that changes nothing', () => {
+    const view = new AnnotationView({ ...note }, 'note');
+    const style = captionOf(view).style;
+    view.redraw();
+    view.sync({ ...note });
+    expect(captionOf(view).style).toBe(style);
+  });
+
+  it('is given a new style for a new width or colour', () => {
+    const view = new AnnotationView({ ...note }, 'note');
+    const style = captionOf(view).style;
+    view.sync({ ...note, w: 260 });
+    const wider = captionOf(view).style;
+    expect(wider).not.toBe(style);
+    expect(wider.wordWrapWidth).toBe(260 - 16);
+    view.sync({ ...note, w: 260, color: 0xffffff });
+    expect(captionOf(view).style).not.toBe(wider);
+    expect(captionOf(view).style.fill).not.toBe(wider.fill);
+  });
+});