enriched-markdown: Android auto-grow input is too tall on first render (mention/link placeholders)

Minimal reproducible example for issue #421 / PR #422.

On Android, an auto-grow EnrichedMarkdownTextInput (scrollEnabled={false}) inside a ScrollView reports a height that is too tall on first render, leaving empty space below the content. It self-corrects on the first keystroke. iOS is unaffected (it measures via TextKit on the already-rendered text).

The defaultValue here is a message template whose placeholders are mention links, e.g. [{firstName}](placeholder://contact.first_name). The label is short on screen but the placeholder://... URL is hidden in the markdown source. InputMeasurementStore.initialMeasure measures the raw markdown (counting those invisible URLs), over-estimating the height into extra lines, until the next text change forces a re-measure.

Environment

• Expo SDK 56, expo-router, React Native 0.85.3, New Architecture enabled
• react-native-enriched-markdown 0.6.0 (unpatched)
• Android only (iOS is the control: correct height from the start)

Run

npm install

# Android: where the bug reproduces
npx expo run:android

# iOS: control, no bug
npx expo run:ios

This is a native module, so a dev build is required (expo run:*). Expo Go will not work.

Steps to reproduce (Android)

1. On Home, tap Open editor.
2. Scroll to the bottom of the message.
3. Bug: there is extra empty space below the last line (the input is taller than its rendered text, so the scroll content extends past the text).
4. Tap the text and type a space (or any character).
5. The input recalculates and snaps to the correct (shorter) height; the extra space disappears.

On iOS the height is correct from the start and does not change on the first keystroke.

Notes

• The bug only shows inside a ScrollView: there the child is measured with UNDEFINED height (its raw auto-grow height), so the over-estimate is visible. Outside a ScrollView an AT_MOST clamp hides it.
• The defaultValue is a long message so it overflows the viewport and runs under the keyboard; scroll to the bottom to see the extra space past the last line. The more/longer the hidden URLs, the larger the over-estimate.

Root cause and fix

InputMeasurementStore.initialMeasure measures the raw markdown source:

val text = props?.getString("defaultValue") ?: props?.getString("placeholder") ?: "I"

PR #422 parses the markdown into its rendered plain text first, using the library's existing parser (the same one setValueFromJS uses), so the first measure matches what is actually rendered:

val markdown = props?.getString("defaultValue") ?: props?.getString("placeholder") ?: "I"
val text = InputParser.parseToPlainTextAndRanges(markdown).plainText

Same family as #281 / #366 (incorrect Android measurement, iOS correct), but on the input component those fixes didn't cover.