Expose the deterministic Falcon-512 (FALCON-DET512) signature scheme from
the falcon library, mirroring the existing Falcon-1024 wrapper: keygen,
signing, verification, and the msgp-serializable key/signature types.

The previously unqualified Falcon names are renamed to Falcon1024* so the
two schemes read symmetrically at call sites. Only Go identifiers change;
the codec tags, and so the wire encoding, are untouched. FalconSeed stays
shared, since a keygen seed is 32 bytes of entropy with no scheme-specific
structure.

1. BottomSheet screen size handle dynamic.
2. BottomSheet handle dynamic for dismissed based on screen
3. OnMinimise back to previous screen

- A frac vote nests a GGovPeriod.vote per re-cast escrow, and that inner vote runs its own checkNeedMBR — which reads `periods` on the gGov registry. Population resolves refs by simulating, so a period that dropped under its minimum balance between simulate and execution failed the whole vote.

- Same fix as the frac registry's `instances` box, one layer down. One slot, not one per escrow: every cast hits the same box. Padding 21 -> 22, fees unchanged.