Reach 100% test coverage with 96% CI guardrail

[coolsam726]

Summary

• Expand the Pest suite with focused coverage for Flatpickr, FlatpickrServiceProvider, hydration/dehydration edge cases, validation, themes, commands, and the facade.
• Add test doubles (StatefulFlatpickr, ParseThrowingFlatpickr) so hydration and exception paths can be exercised without a mounted Filament form container.
• Add minimal package fixtures (stubs/flatpickr-field.stub, database/migrations/) so service-provider boot paths are covered.
• Enforce a 96% coverage floor via pest --coverage --min=96 in CI and the composer test-coverage script.

Coverage

Area	Before	After
Total	58.1%	100%
Forms/Components/Flatpickr	57.9%	100%
FlatpickrServiceProvider	62.3%	100%

Notable test additions

• Hydration: single/range/multiple, native vs non-native, time-only and datetime paths
• Dehydration: native formatting, brute-force range splitting, parse exceptions
• Validation: array/null states for range and multiple pickers
• Service provider: install force-publish, stub publishing, migration registration
• Attributes, view helpers, theme assets, console commands

Test plan

• vendor/bin/pest --coverage --min=96 passes locally (114 tests)
• vendor/bin/pint --test passes
• CI matrix passes with the new coverage gate