Paste-back (ctrl+v) truncates filenames at the first space

Found during OSV work (the two standing uitest ctrl+v failures are this defect, not flakes): `Framing::read_line` takes the first whitespace-delimited word as the filename, so any file with a space in its name cannot be pasted back — e.g. the DJI corpus files (`1 8k30p standard 10bit iso max 800-003.OSV`).

`framing.rs`; pre-existing on main (not introduced by any current branch). The view-line paste path parses the rest of the line (time=/yaw=/...) correctly; only the filename tokenization is wrong. Needs a quoting or last-token-aware parse, plus a uitest case with a spaced filename.

Filed under the standing issue-filing authorization.