[Bug]: iOS composer never grows with the prompt, and its controls ignore taps while the editor is focused

Before submitting

• I searched existing issues and did not find a duplicate.
• I included enough detail to reproduce or investigate the problem.

Area

apps/mobile (iOS, App Store 1.1.0)

Steps to reproduce

1. Open a thread on an iPhone and tap the composer so the keyboard comes up.
2. Paste or type a prompt of five or six sentences (six sentences of lorem ipsum is enough).
3. Try to read back what you wrote.
4. Tap the model chip, the mic, the plus, or send while the keyboard is still up.

Expected behavior

The box grows with the prompt up to its maximum height, and the composer controls respond to taps while I am still typing.

Actual behavior

• The box stays two lines tall no matter how long the prompt is. Everything past the second line is invisible while writing.
• The second visible line is cut in half by the bottom edge of the box.
• The model chip and the mic are drawn on top of the text, so the words run underneath them and both become unreadable.
• While the editor has focus, nothing in the composer responds to taps: plus, model chip, mic, send.
• Dismissing the keyboard makes every control work again. Dictation and pasted citations also work, because both leave the editor unfocused.
• There is a large empty area above the composer that the box never uses.

Impact

Anything longer than two lines has to be written blind, and every send needs the keyboard dismissed first. On a phone this makes long prompts impractical.

Version or commit

1.1.0 (App Store)

Environment

iPhone 17 Pro, iOS 26.6, portrait, dark mode, English and Polish keyboards.

Screenshots, recordings, or supporting files

Workaround

Dismiss the keyboard before tapping anything in the composer, or dictate instead of typing.

Related

#11757 and #11944 look like they cover the growth and the chip overlay respectively. #11755 was closed as not reproducible on TestFlight, but the current App Store build still behaves this way. Happy to test a TestFlight build if that would help.

Start in apps/mobile with the iOS composer implementation, then inspect related PRs #11757 and #11944 before changing anything. Reproduce with a multiline prompt while the keyboard is open and verify that the composer grows without clipping or overlap and that the model chip, mic, plus, and send controls respond while the editor remains focused.