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

THIRD_PARTY_LICENSES

@@ -361,7 +361,22 @@ https://www.apache.org/licenses/LICENSE-2.0
 
 ---
 
-## 13. IconFontCppHeaders
+## 13. Material Design Icons Pickaxe Subset Font
+
+- **Location:** `res/fonts/MaterialDesignIcons-Pickaxe-Subset.ttf`
+- **Source:** https://github.com/Templarian/MaterialDesign-Webfont
+- **Derived from:** Pictogrammers Material Design Icons webfont (`materialdesignicons-webfont.ttf`)
+- **Copyright:** Pictogrammers contributors
+- **License:** Apache License 2.0
+
+This bundled font is a local one-glyph subset containing only the MDI pickaxe
+icon, remapped onto a BMP private-use codepoint for Dear ImGui compatibility.
+The full text of the Apache License 2.0 is available at:
+https://www.apache.org/licenses/LICENSE-2.0
+
+---
+
+## 14. IconFontCppHeaders
 
 - **Location:** `src/embedded/IconsMaterialDesign.h`
 - **Source:** https://github.com/juliettef/IconFontCppHeaders
@@ -390,7 +405,7 @@ freely, subject to the following restrictions:
 
 ---
 
-## 14. Ubuntu Font Family
+## 15. Ubuntu Font Family
 
 - **Location:** `res/fonts/Ubuntu-Light.ttf`, `Ubuntu-Medium.ttf`, `Ubuntu-R.ttf`
 - **Source:** https://design.ubuntu.com/font