feat: all AI formats printable, crop-vs-border rule, mobile layout, Passbilder rename

Print now offers every format the AI pipeline knows (9x13 to 60x90, DIN A6-A2,
squares, poster/frame sizes to 70x100, and the screen ratios as physical sizes).
When a picture does not match the target ratio the user picks per image between
cropping to fill and keeping the whole picture on a border colour - never a
stretch. The module is called Passbilder now; /druck redirects.

Fixes two real defects: sharp runs extend after resize, so padded cells came out
oversized (a 35x45 mm cell became 35x171 mm with a border), and the grid packer
rotated a single portrait photo just because more would fit sideways.

Mobile: cards become rows, touch targets ~40px, crop editor as a bottom sheet.
Verified at 390/820/1440px - all three produce the same PDF.

src/pages/druck.astro

@@ -1,16 +1,4 @@
 ---
-import Base from '../layouts/Base.astro';
-import PrintApp from '../components/PrintApp.tsx';
+// Alte Adresse — die Funktion heißt jetzt „Passbilder".
+return Astro.redirect('/passbilder', 301);
 ---
-<Base title="Druck · Klarbild">
-  <h1 class="seiten-titel">Druck</h1>
-  <p class="seiten-lead">
-    Bilder ohne KI auf exakte Maße bringen und mehrere davon in 100 %-Größe mit
-    Schnittmarken auf einen Bogen setzen — Passbildsatz, Kita-Bilder, Sticker.
-  </p>
-  <PrintApp client:load />
-  <style>
-    .seiten-titel{font-family:var(--font-display);font-size:1.6rem;margin:6px 0 4px;letter-spacing:-.02em;}
-    .seiten-lead{color:var(--soft);font-size:13.5px;margin:0 0 16px;max-width:64ch;line-height:1.55;}
-  </style>
-</Base>