InputController.handleFollowUp read raw editor text via getText(),
bypassing the paste-store expansion the Enter path applies through
Editor.getExpandedText(). A large paste collapsed into a [Paste #N, +X
lines] marker was therefore sent verbatim to the model when queued with
Ctrl+Q / Ctrl+Enter, silently dropping the pasted content.
Switch the follow-up path to getExpandedText() so queued submissions
match the Enter path. Image markers are untouched; pendingImages
forwarding is unchanged.
Updated existing input-controller stubs (skill-queue, followup-image,
keybindings) to implement getExpandedText, matching the production
CustomEditor surface.
Fixes#3737