Add date and time pickers with calendar popups and HTML mappings

- Add CalendarDate, TimeOfDay, LocalDateTime and DateRange with Gregorian
  arithmetic, locale-aware formatting/parsing, ISO serialization and Unix
  timestamp conversions with explicit UTC offsets.
- Add UIDateTimeEdit, UIDatePicker, UITimePicker, UIDateTimePicker and
  standalone UICalendar, with XML/CSS registration and data binding.
- Support segmented keyboard editing, numeric entry, ISO paste, configurable
  steps, bounds, empty values and independent seconds/milliseconds display.
  Default time display to hours and minutes while preserving stored precision.
- Add day/month/year calendar navigation and a combined date-time popup with
  time steppers, live configuration updates and scoped event connections.
- Add Breeze and fallback theme styles with CSS-defined SVG icons, dp sizing,
  font-aware calendar dimensions and muted read-only/disabled controls.
- Map HTML date, time and datetime-local inputs to native controls with strict
  value sanitization, min/max/step/required/readonly/disabled handling,
  constraint validation and normalized form serialization.
- Provide private light HTML control defaults and intrinsic temporal sizing;
  prevent author CSS from styling anonymous implementation parts.
- Share popup placement and visibility helpers across pickers, dropdowns and
  trigger/cursor menus while retaining cascading-menu placement rules.
- Fix fractional grid wrapping and input cursor bubbling over child buttons;
  notify and refresh styles when editing permission changes.
- Reduce CSS registration allocations with string_view parameters and
  heterogeneous name lookup; inline frequently used node and CSS getters.
- Align CodeEditor default font sizing with text widgets without overriding
  application preferences.
- Add HTML form margin defaults and update the affected rendering baseline.
- Upgrade Windows ecode nightly builds to Ubuntu 24.04 and newer MinGW.
- Add picker documentation, an example and regression coverage for date math,
  locales, editing, popup placement/lifetime, HTML controls and pixel density

.github/workflows/ecode-nightly.yml

@@ -201,7 +201,7 @@ jobs:
         config:
           - compiler: default
             arch: x86_64
-            container: ubuntu-22.04
+            container: ubuntu-24.04
     runs-on: ${{ matrix.config.container }}
     env:
       CC: gcc
@@ -222,17 +222,9 @@ jobs:
           sudo apt-get update
       - name: Install dependencies
         run: |
-          sudo apt-get install -y premake4 libfuse2 fuse mingw-w64 gcc-12 g++-12
+          sudo apt-get install -y premake4 libfuse2t64 fuse mingw-w64
           wget https://cdn.ensoft.dev/eepp-assets/premake-5.0.0-beta6-linux.tar.gz
           tar xvzf premake-5.0.0-beta6-linux.tar.gz
-          sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-12 10
-          sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-12 10
-          sudo update-alternatives --install /usr/bin/cc cc /usr/bin/gcc 30
-          sudo update-alternatives --set cc /usr/bin/gcc
-          sudo update-alternatives --install /usr/bin/c++ c++ /usr/bin/g++ 30
-          sudo update-alternatives --set c++ /usr/bin/g++
-          sudo update-alternatives --config gcc
-          sudo update-alternatives --config g++
       - name: Build ecode
         run: |
           bash projects/scripts/patch_commit_number.sh