feat(addresses): improve address labeling and view-only handling

- Add expanded address icon picker with search, bottom-aligned actions, and improved modal sizing
- Embed a pickaxe icon font subset and wire it into typography/address icon rendering
- Track view-only shielded addresses and prevent sends from non-spendable z-addresses
- Improve address transfer dialog sizing, max amount handling, and text clipping
- Tune main header layout values in ui.toml
- Update README, codebase overview, and third-party license documentation

src/util/i18n.cpp

@@ -434,6 +434,8 @@ void I18n::loadBuiltinEnglish()
         strings_["label_placeholder"] = "e.g. Savings, Mining...";
         strings_["choose_icon"] = "Choose Icon";
         strings_["clear_icon"] = "Clear Icon";
+        strings_["search_icons"] = "Search icons...";
+        strings_["no_icons_found"] = "No icons match your search.";
         strings_["transfer_funds"] = "Transfer Funds";
         strings_["transfer_to"] = "Transfer to:";
         strings_["deshielding_warning"] = "Warning: This will de-shield funds from a private (Z) address to a transparent (T) address.";