feat: add maxLength support to EnrichedTextInput

[xiamu14]

Summary

• add maxLength support to EnrichedTextInput
• emit onMaxLengthExceeded when native input rejects text that would exceed the limit
• wire the new prop through the JS/native bridge on Android and iOS

Why

Some apps need to block rich-text input before content is inserted, instead of accepting text and reverting it afterward. This is especially important for candidate insertion and other multi-character commits.

Notes

• Android rejects overflow using an input filter and emits onMaxLengthExceeded
• iOS rejects overflow inside shouldChangeTextInRange and emits onMaxLengthExceeded
• JS exposes both maxLength and onMaxLengthExceeded

Validation

• verified app-side integration against a local package copy in a consumer app
• linted the consumer integration file and the native bridge entry updates locally