docs(date-range-field): el ultimo fantasma — readonlySegments nunca fue simetrico

El README documentaba `readonlySegments` "aplicado simetricamente a ambos
extremos"; esa prop no existe. La API real es por-extremo desde types.ts:
`startReadonlySegments` / `endReadonlySegments` (el input deriva
`endpointReadonlySegments` segun su type). La fila de la tabla de props y la
fila comparativa quedan alineadas con el codigo.

Era el unico fantasma real de los 5 que dejo el barrido exhaustivo: los otros
4 eran falsos positivos del extractor por indireccion de tipos (props
importadas + rest-forwarding) — la leccion que dicta la resolucion a un salto
del invariante I10 del guard.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/uix/soma/components/date-range-field/README.md

@@ -95,7 +95,7 @@ See `types.ts` for the JSDoc-documented surface. Summary:
 | `minValue` / `maxValue`  | `DateValue`                   | Bound applied to both endpoints.                 |
 | `disabled` / `readonly`  | `boolean`                     | Merged with parent Field if present.             |
 | `required`               | `boolean`                     | Hidden inputs required on form submit.           |
-| `readonlySegments`       | `EditableSegmentPart[]`       | Applies symmetrically to both endpoints.         |
+| `startReadonlySegments` / `endReadonlySegments` | `EditableSegmentPart[]` | Per-endpoint read-only segments.  |
 | `granularity`            | `'day' \| 'hour' \| 'minute' \| 'second'` | Drives segment set for both inputs.  |
 | `hourCycle`              | `12 \| 24`                    | Numeric. Falls back to locale.                   |
 | `hideTimeZone`           | `boolean`                     | Hide tz segment on ZonedDateTime.                |
@@ -127,7 +127,7 @@ The range validator runs when both endpoints are set and fires `onInvalid` with
 | Range-level `validate`               | ✓                | ✓                | ✓                | ✓                            |
 | Natural order check (`end >= start`) | ✓                | ✓                | ✓                | ✓                            |
 | `minValue` / `maxValue` shared       | ✓                | ✓                | ✓                | ✓                            |
-| Per-segment `readonlySegments`       | ✗                | ✗                | ✓                | ✓ (adopted)                  |
+| Per-segment read-only (`start`/`endReadonlySegments`) | ✗   | ✗                | ✓                | ✓ (per endpoint)             |
 | Shared locale / granularity / hourCycle | ✓             | ✓                | ✓                | ✓                            |
 | Per-endpoint DateField context       | ✓                | ✓                | ✓                | ✓ (each Input creates one)   |
 | `hh`/`mm`/`ss` placeholders          | ✗ (`--`)         | ✗ (`--`)         | ✗ (`--`)         | ✓                            |