fix: pre-release issues for 0.2.0 (user-input-only change events, sheet width, label alignment, Blazor Hybrid, chart names)

[Shewart]

Fixes the issues found by FDMS, the first real consumer, before the 0.2.0 release.

Changes

• Change events report user input only (Change events fire when the value is set from code #24, breaking). Toggled, CheckedChanged, ValueChanged, SelectedIndexChanged, SelectedValueChanged, PageChanged, DateChanged, TimeChanged, ItemToggled and the other value and selection events fire only for clicks, taps, swipes and keys, like Radix's onValueChange. Setting the value from code or a binding no longer raises them; watch the property to see every change. 30 components on MAUI and Avalonia. Unchanged: text fields' TextChanged, overlay open events, ThemeChanged, FileUpload.FilesChanged, Sidebar.IsCollapsedChanged
• Sheet width (Sheet width can't be changed #26): SheetContent.MaxPanelWidth (default 384, never more than 75% of the window), MAUI and Avalonia
• ShellLabel (ShellLabel: add HorizontalTextAlignment and LineBreakMode #27): HorizontalTextAlignment and LineBreakMode on MAUI (Avalonia's ShellLabel is a TextBlock and already has them)
• Next to ShellUI Blazor (Blazor Hybrid guide: both CLIs default to the same components folder #28): init uses Components/Native when it finds shellui.json, and the components namespace follows the folder (Components/UI gives the same code as before). The Blazor Hybrid guide covers the order of the two inits, and its examples build
• Blazor Hybrid build fix: MAUI Shell.cs names Microsoft.Maui.Controls.Layout in full; a hybrid app's <App>.Components.Layout namespace made the bare name fail (CS0118). A test keeps bare Layout out of the MAUI templates
• Charts named as in ShellUI: donut-chart is its own component (DonutChart.cs, depends on pie-chart), so add donut-chart, add radial-chart, add bar-chart work and list shows them like ShellUI (Blazor). Unknown names in add / remove / update get "Did you mean …?"
• Dependency audit test: every type a component uses from another component must come from its declared dependencies, its family or shell, on both platforms (230 cases), so a component added on its own always builds
• Docs: "Change events" section in COMPONENTS.md, label / sheet / chart notes, QUICKSTART, CLI README, plan

Verification

• Every commit builds and passes its tests on its own; head: solution 0 warnings / 0 errors on all MAUI targets, 1462 tests (CI green), dotnet format clean
• A fresh dotnet new maui-blazor app with shellui init + add button and shellui-native init + add button builds 0/0 (fails with 0.1.0-alpha.2), and so does the guide's MainPage example
• add donut-chart in fresh MAUI and Avalonia apps installs chart → pie-chart → donut-chart and builds 0/0; switch, select, multi-select, data-table, carousel and sidebar each in a fresh Avalonia app build 0/0
• Templates match the demo components exactly (the sync writes nothing)
• Event behaviour checked at run time on both platforms: values set from code raised no events on switch, checkbox, toggle, slider (including new Minimum / Maximum), tabs, pagination, accordion, collapsible and select; key presses (Avalonia) and the controls' own tap handlers (MAUI, Windows) raised one each

Not included

• Buttons and sidebar items can't be invoked through UI Automation on Windows #25 (Windows UI Automation), Keep the theme in sync between native and Blazor UI in hybrid apps #29 (hybrid theme sync), CLI: support NuGet dependencies so components can use ShellIcons #30 (NuGet dependencies in the CLI)

Closes #24, #26, #27, #28