feat(ui): use floating prompt for filter fallback

[gvanderclay]

Summary

Use the plugin floating prompt for filter input when Telescope is unavailable, so fallback filters update while the user types instead of waiting for Enter.

Changes

• Route no-Telescope filter_input calls through android.ui.input.
• Keep the editable input line clean and derive the floating title from the existing prompt_title.
• Open existing filter text in append mode with startinsert!.
• Make the floating input wider by default and size it with strdisplaywidth().

Testing

• ./scripts/run-tests.sh
• Relevant single test(s): ./scripts/run-tests.sh tests.android.ui.input_test tests.android.ui.picker.picker_filter_input_test tests.android.logcat.controls.filter_input_test tests.android.logcat.controls.package_test

Docs

• README updated (if needed): not needed
• docs/ updated (if needed): not needed
• docs navigation updated for moved or renamed pages: not needed
• command/config behavior reflected in reference docs: not needed, no command or config change
• user workflow changes reflected in guides: not needed
• CHANGELOG updated (user-visible changes)
• Config changes or new defaults noted: no config change

Checklist

• Behavior is backward compatible or clearly documented
• No unrelated changes included