Add min/max cross-validation to NumberAttributesEditor

[JeroenDeDauw]

Prompted by @JeroenDeDauw, implemented autonomously by Claude Code.
Context: the NeoWiki codebase, issue #476 and comment, and TextAttributesEditor as reference.
_{Written by Claude Code, Opus 4.6}

Fixes #476

NumberAttributesEditor was missing the validation refinements that
TextAttributesEditor received in PR #551. This adds:

• Error state when minimum exceeds maximum (and vice versa)
• Local input refs with watchers for all fields (minimum, maximum,
  and precision) so in-progress input is preserved even when invalid
• New i18n message neowiki-property-editor-min-exceeds-max
• Extracted shared minExceedsMax helper used by both Text and Number
  editors
• Moved FieldProps test interface to shared VueTestHelpers
• CSS classes on min/max fields for robust test selectors

[alistair3149]

Code review requested by @alistair3149.
Context: the NeoWiki codebase, PR #722 diff, TextAttributesEditor reference from PR #551, and AGENTS.md conventions.
_{Written by Claude Code, Opus 4.6}

Issues

Important

1. Precision field still has the exact bug this PR fixes for min/max.

File: resources/ext.neowiki/src/components/SchemaEditor/Property/NumberAttributesEditor.vue:42-47, 78-88

updatePrecision reads property.precision directly and never mirrors into a local ref. When invalid input is typed (e.g. -5), precisionError is set but nothing is emitted — so the parent's property.precision never updates, the reactivity of precisionError triggers a re-render, and :model-value re-evaluates to the old prop value, snapping the display back and losing the user's -5.

Suggested fix (~5 lines, matches the min/max pattern just established):

const precisionInput = ref( props.property.precision?.toString() ?? '' );

watch( () => props.property.precision, ( newVal ) => {
    precisionInput.value = newVal?.toString() ?? '';
} );

const updatePrecision = ( value: string ): void => {
    precisionInput.value = value;
    const numValue = parseNumber( value );
    // ...rest unchanged
};

And bind :model-value="precisionInput" in the template.

The existing test 'shows error and does not emit when precision is negative' (NumberAttributesEditor.spec.ts:151) only asserts error status and no emit — it starts from precision: undefined, so it can't observe the snap-back. A regression test for this specific behavior should be added (and will fail against the current code, confirming the bug):

it( 'preserves invalid input in the precision field', async () => {
    const wrapper = newWrapper( {
        property: newNumberProperty( { precision: 2 } ),
    } );
    const inputs = wrapper.findAllComponents( CdxTextInput );

    await inputs[ 2 ].vm.$emit( 'update:modelValue', '-5' );

    expect( inputs[ 2 ].props( 'modelValue' ) ).toBe( '-5' );
} );

The same pattern is worth adding for min/max — neither the Text nor Number spec currently exercises the watcher that re-syncs the local input when the parent updates the prop externally, and that's the subtlest part of the in-progress-input preservation.

2. minExceedsMax is duplicated byte-for-byte across two components.

• resources/ext.neowiki/src/components/SchemaEditor/Property/NumberAttributesEditor.vue:79-83
• resources/ext.neowiki/src/components/SchemaEditor/Property/TextAttributesEditor.vue:107-111

AGENTS.md explicitly says not to duplicate in production code. Now is the right moment to extract to a shared helper — the second copy just arrived.

Minor

3. Fragile positional indexing in test helpers.

File: resources/ext.neowiki/tests/components/SchemaEditor/Property/NumberAttributesEditor.spec.ts:32-40

fields[length - 3] / length - 2 breaks opaquely if another CdxField is ever added. Prefer class-based lookup (e.g. number-attributes__minimum / __maximum) matching the style the precision field already uses.

4. FieldProps interface duplicated between Text and Number specs. Small test-helper duplication — worth extracting to VueTestHelpers.ts for the next editor that needs the pattern.

[JeroenDeDauw]

Should be fixed now