fix(geschichte): raise journey reading text to the accessibility floor

Intro, letter titles, curator annotations, and interludes rendered at
12-14px — copied from the scaled mockup sizes in LR-2. Narrative text
is now 16-18px, meta lines and links 14px; the LR-2 impl-ref table is
updated to match.

Closes #800
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs/specs/lesereisen-reader-spec.html

@@ -636,19 +636,19 @@
             <tr><td>Metabar</td><td>flex items-center gap-3 pb-4 border-b border-subtle mb-4</td><td>gleich wie Story</td></tr>
             <tr><td>Bearbeiten/Löschen</td><td>nur BLOG_WRITE; auf Mobile im ··· BottomSheet</td><td>gleich wie Story</td></tr>
             <tr class="grp"><td colspan="3">Intro-Absatz</td></tr>
-            <tr><td>Intro (body)</td><td>font-serif text-sm text-ink-2 italic leading-relaxed mb-6 pb-4 border-b border-dashed border-subtle</td><td>nur rendern wenn body nicht leer; kein HTML-Rendering — plaintext</td></tr>
+            <tr><td>Intro (body)</td><td>font-serif text-lg text-ink-2 italic leading-relaxed mb-6 pb-4 border-b border-dashed border-subtle</td><td>nur rendern wenn body nicht leer; kein HTML-Rendering — plaintext</td></tr>
             <tr class="grp"><td colspan="3">Dokument-Item</td></tr>
             <tr><td>Item-Zeile</td><td>mb-3</td><td>kein flex nötig — Karte ist full-width</td></tr>
             <tr><td>Dokumentkarte</td><td>bg-surface border border-line rounded-sm p-3</td><td></td></tr>
-            <tr><td>Brieftitel</td><td>font-serif text-sm text-ink leading-snug mb-0.5</td><td>document.title</td></tr>
-            <tr><td>Briefmeta</td><td>text-xs text-ink-3 mb-2</td><td>formatDate(document.documentDate) · "von X an Y"</td></tr>
-            <tr><td>Brief öffnen Link</td><td>inline-flex items-center gap-1 text-xs font-semibold text-ink hover:text-primary</td><td>href="/documents/{item.document.id}"</td></tr>
+            <tr><td>Brieftitel</td><td>font-serif text-base text-ink leading-snug mb-0.5</td><td>document.title</td></tr>
+            <tr><td>Briefmeta</td><td>text-sm text-ink-3 mb-2</td><td>formatDate(document.documentDate) · "von X an Y"</td></tr>
+            <tr><td>Brief öffnen Link</td><td>inline-flex items-center gap-1 text-sm font-semibold text-ink hover:text-primary</td><td>href="/documents/{item.document.id}"</td></tr>
             <tr class="grp"><td colspan="3">Kuratoren-Annotation</td></tr>
             <tr><td>Annotation</td><td>mt-3 pl-3 border-l-2 border-brand-mint bg-muted rounded-r-sm py-1.5 pr-2</td><td>nur rendern wenn item.note vorhanden</td></tr>
-            <tr><td>Annotations-Text</td><td>text-xs italic text-ink-2 leading-relaxed</td><td></td></tr>
+            <tr><td>Annotations-Text</td><td>text-base italic text-ink-2 leading-relaxed</td><td></td></tr>
             <tr class="grp"><td colspan="3">Interlude-Item</td></tr>
             <tr><td>Interlude-Block</td><td>pl-3 border-l-2 border-orange-400 bg-orange-50 rounded-r-sm py-2 pr-3 my-4</td><td>item.document === null</td></tr>
-            <tr><td>Interlude-Text</td><td>text-xs italic text-ink leading-relaxed</td><td>item.note; plaintext</td></tr>
+            <tr><td>Interlude-Text</td><td>text-base italic text-ink leading-relaxed</td><td>item.note; plaintext</td></tr>
             <tr class="grp"><td colspan="3">Mobile</td></tr>
             <tr><td>··· Menü</td><td>ml-auto text-ink-3; öffnet BottomSheet mit Bearbeiten + Löschen</td><td>BLOG_WRITE; gleich wie Story</td></tr>
             <tr><td>Touch Target (Brief öffnen)</td><td>min-h-[44px] durch padding auf der Karte</td><td>WCAG 2.2 AA</td></tr>