feat(contacts): richer edit-dialog avatar picker (preview, chips, image, icons)

Four refinements now that the two-column layout has room:

1. Image mode shows a large circular preview of the chosen picture (or a
   placeholder circle with an add-photo glyph, or a broken-image glyph if the
   file went missing), the filename, and centered Choose/Remove buttons —
   instead of a bare button.
2. The live-preview avatar is larger (r20 → r26) and the address is now
   middle-truncated (head + tail) so both ends read, like the real list row.
3. Badge mode shows the two actual chips — Z (shielded) and T (transparent) —
   with labels, making clear the badge is auto-picked from the address type,
   rather than a line of text.
4. The Badge/Icon/Image segmented control gains glyphs (badge / palette /
   image) beside its labels via a small two-font inline control (the shared
   SegmentedControl helper is single-font).

Adds contact_avatar_shielded / _transparent keys and rewords the badge hint
(the chips now carry the Z/T meaning); +8-language translations, all within
the existing CJK subset.

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

res/lang/de.json

@@ -289,13 +289,15 @@
     "console_zoom_out": "Verkleinern",
     "contact_avatar": "AVATAR",
     "contact_avatar_badge": "Abzeichen",
-    "contact_avatar_badge_hint": "Verwendet das Adresstyp-Abzeichen – Z für abgeschirmt, T für transparent.",
+    "contact_avatar_badge_hint": "Das Abzeichen wird automatisch anhand des Adresstyps gewählt.",
     "contact_avatar_choose": "Bild auswählen…",
     "contact_avatar_copy_failed": "Dieses Bild konnte nicht kopiert werden.",
     "contact_avatar_icon": "Symbol",
     "contact_avatar_image": "Bild",
     "contact_avatar_image_hint": "Das Bild wird in die App kopiert, damit es verfügbar bleibt, wenn das Original verschoben wird.",
     "contact_avatar_remove": "Entfernen",
+    "contact_avatar_shielded": "Abgeschirmt",
+    "contact_avatar_transparent": "Transparent",
     "contact_global": "In jeder Wallet anzeigen (globaler Kontakt)",
     "contact_global_badge_tt": "Globaler Kontakt — in jeder Wallet sichtbar",
     "contact_global_tt": "Ein: Dieser Kontakt bleibt sichtbar, egal welche Wallet Sie laden. Aus: Er gehört nur zur aktuellen Wallet.",