refactor(firmware): remove the retired simulation workflow

Remove the retired simulator workspace member, dependencies, workflow
and documentation. Keep the shared flight and hardware crates.

Validation: retirement prefix host check, command-dispatch tests and
book build.

docs/src/architecture.md

@@ -55,10 +55,9 @@ one complete replacement candidate. The core distinguishes only immutable
 boot-active values from the latest committed values. A save cannot mutate
 controller or estimator state in flight.
 
-Target-owned stores use private persistence formats. SITL atomically replaces a
-bounded CBOR snapshot. F722 alternates compact `KCSP` snapshots between two
-erase sectors, retaining only the old and replacement records across the commit
-boundary. Neither format is exposed as the public KCFG file.
+Target-owned stores use private persistence formats. F722 alternates compact
+`KCSP` snapshots between two erase sectors, retaining only the old and
+replacement records across the commit boundary. That format is not exposed as the public KCFG file.
 Motor allocation/mixer topology is immutable compiled vehicle capability data,
 never a scalar field or persistence member. F722 recovers operational settings
 before constructing consumers. Its local USB CDC-ACM and directly wired UART