Fix the crosshair name on the Setups page

[rndaom]

The Setups page read "Execs crosshairs" as the crosshair for every setup with the crosshair pack on. The overview filled crosshair from CrosshairRecord.id, which is the pack id (execs-crosshairs), not the crosshair.

Changes

• setup_overview.rs: crosshair is now the record's shape, which is the crosshair every weapon gets. Per-weapon assignments aren't listed. It is still None when the pack is off, and also when an old record has no shape.
• New crosshairDesign field: the saved designer parameters for that shape when it is one of the player's designs. It handles both stored forms of design: a single design for designed, or a map of library name to design. factValue passes it to crosshairLabel, so a design shows under its saved name rather than a name rebuilt from its slug or "My crosshair".
• sameFact also compares the design, so two setups using designed with different designs count as different.
• The bridge.ts doc comment now describes the shape. Fixtures are updated.
• Test: crosshair_hud_sounds_and_mods_come_from_the_manifest used to build a record with "id": "dot", which hid this bug. It now uses a realistic record (id: "execs-crosshairs", a shape, a per-weapon assignment) and covers both design forms and the inactive pack.

Checks

• cargo fmt --all --check, cargo clippy --workspace --all-targets -- -D warnings, cargo test --workspace --locked
• pnpm check, pnpm test