Remove the FileDef preview stage's floating provenance tag

packages/base/file-formats/file-preview-stage.gts

@@ -114,21 +114,6 @@ export class FilePreviewStage extends GlimmerComponent<StageSignature> {
     return this.showGenericDetail ? '44' : '30';
   }
 
-  get srcTag() {
-    return (this.model?.previewSource ?? '').toUpperCase();
-  }
-
-  // Provenance is only meaningful for the families that actually render
-  // something; a generic pane has nothing to attribute.
-  get showSrcTag() {
-    return (
-      this.showReal &&
-      Boolean(this.args.preview) &&
-      Boolean(this.model?.previewSource) &&
-      this.model?.previewSource !== 'fallback'
-    );
-  }
-
   <template>
     <div
       class='stage'
@@ -189,9 +174,10 @@ export class FilePreviewStage extends GlimmerComponent<StageSignature> {
         {{#if (eq this.state 'malformed')}}
           <div class='malformed-banner'>Partial · some content unreadable</div>
         {{/if}}
-        {{#if this.showSrcTag}}
-          <span class='src-tag'>{{this.srcTag}}</span>
-        {{/if}}
+        {{! No provenance overlay: a tag floated over the render lands on
+        whatever the family draws in that corner — a prose preview's title, an
+        archive tree's first row — and provenance already has a home in the
+        isolated shell's metadata chrome. }}
       {{else if (eq this.state 'loading')}}
         <div class='state-pane'>
           <div class='skeleton-bar'></div>
@@ -367,19 +353,6 @@ export class FilePreviewStage extends GlimmerComponent<StageSignature> {
         color: var(--fd-warn, #e8710a);
         text-align: left;
       }
-      .src-tag {
-        position: absolute;
-        top: 8px;
-        left: 8px;
-        font-family: var(--font-mono);
-        font-size: 0.4375rem;
-        letter-spacing: 0.06em;
-        color: var(--muted-foreground);
-        background: rgb(255 255 255 / 62%);
-        padding: 2px 4px;
-        border-radius: 2px;
-        text-transform: uppercase;
-      }
       @keyframes fd-shimmer {
         0% {
           background-position: -180% 0;

packages/host/tests/integration/components/file-def-format-templates-test.gts

@@ -184,6 +184,40 @@ module('Integration | FileDef format templates', function (hooks) {
     assert.dom('[data-test-file-no-preview]').doesNotExist();
   });
 
+  // The stage floats no chrome over the family's render: an overlay in the
+  // stage's corner lands on whatever the preview draws there — a prose
+  // preview's title, an archive tree's first row. Provenance lives in the
+  // isolated shell's metadata chrome instead.
+  test('the stage renders no provenance overlay in any format', async function (assert) {
+    const ReportPreview: TemplateOnlyComponent<FilePreviewSignature> =
+      <template>
+        <div data-test-report-preview>{{@model.name}}</div>
+      </template>;
+
+    class ReportDef extends FileDef {
+      static displayName = 'Report';
+      static previewComponent = ReportPreview;
+    }
+
+    let file = new ReportDef({
+      id: 'http://example.com/docs/report.pdf',
+      url: 'http://example.com/docs/report.pdf',
+      sourceUrl: 'http://example.com/docs/report.pdf',
+      name: 'report.pdf',
+      contentType: 'application/pdf',
+    });
+
+    for (let format of ['embedded', 'isolated', 'fitted'] as const) {
+      await renderCard(loader, file, format);
+      assert
+        .dom('[data-test-report-preview]')
+        .exists(`the preview mounts in ${format}`);
+      assert
+        .dom('[data-test-file-preview-stage] > span, .src-tag')
+        .doesNotExist(`${format} floats no tag over the render`);
+    }
+  });
+
   // The shells read the glyph from the class rather than from a family→glyph
   // map, which is what keeps each family's icon module out of card-api's
   // dependency graph — and so out of every card's. If a shell ever goes back to