v3.5.0: Friendly picker as open dossiers

Friendly picker

•	Every pregen is an open folder on the black page. The inside flap carries the MORS ET SCIENTIA seal stamped in the group's ink, each at its own tilt, plus a pencilled case number, birth and nationality.
•	About one file in three has a pencilled remark drawn from the pregen itself: a Bond, a weapon, their best skill or a Motivation.
•	The typed sheet leads with the profession, then the name, HP / WP / SAN / BP and the three best skills. The group is a coloured tab on the folder's edge.
•	"Hand me a dossier" (was "Deal me an Agent") is a paper-clipped slip. The group filter uses short names with a coloured dot.
•	While choosing, the folder frame is hidden. After "Choose a different Agent", a "Back to …'s file" link returns to the dossier.
•	The dossier itself is unchanged.

Frontend only: no backend, rules or Cloud Functions change.