Replace Frappe Charts with Orchid Charts and simplify the PHP API

[tabuna]

Replace Frappe Charts with @orchidsoftware/charts 0.0.8 and let screens configure charts directly through the PHP layout API, without a dedicated chart class.

Layout::chart('visits', 'Visits')
    ->height(300)
    ->smooth()
    ->gradient();

The screen query supplies shared labels and datasets:

'visits' => [
    'labels' => ['Mon', 'Tue'],
    'datasets' => [
        ['name' => 'Visits', 'values' => [12, 18]],
    ],
],

Changes

• Support line, bar, mixed, pie, and percentage charts with native Orchid Charts options, markers, and SVG export.
• Update metric collections, example screens, and the orchid:chart generator to the new PHP API and data format.
• Use the package's hover styling variables for a neutral highlight and refresh example data with a gradient on the main line chart.
• Reserve the configured chart height in the initial HTML to prevent layout shifts while charts load.
• Handle configuration and canvas updates in the controller, clean up chart instances on disconnect, and rebuild the distributed assets without Frappe.

Breaking changes

• Chart data now uses shared labels and datasets; labels inside individual datasets are no longer the supported format. TimeCollection::toChart() and GroupCollection::toChart() return the new shape.
• Frappe-specific options are replaced by native Orchid Charts options. TYPE_MIXED replaces TYPE_AXIS_MIXED.
• Pie and percentage charts require exactly one dataset instead of silently aggregating multiple datasets.
• Chart properties are typed; custom subclasses should configure charts through fluent methods, as the updated generator does.

Validation

• Production asset build passed.
• Six JavaScript controller tests passed.
• Full PHP suite passed: 624 tests and 1,697 assertions. After adding the generator regression and fixing its stub, the focused generator, chart layout, and metrics suite passed: 23 tests and 82 assertions.
• Scoped Pint checks and git diff --check passed.

The previous PR revision had unrelated Psalm failures concerning PhpVersionNotSupportedException and Dusk failures in notification badges and the item creation modal. Those areas are outside this change; CI will run again on this revision.