- Rename Sgp4.sgp4_init to Sgp4.init (E330 redundant module prefix)
- Fix doc style for Spdx.checksum_jsont and Spdx.document (E410)
- Flatten test suites to single pair per E600 convention

Add READMEs for: ocaml-fdir, ocaml-initramfs, ocaml-jailhouse,
ocaml-linkedin, ocaml-openamp, ocaml-pid1, ocaml-rpmsg, ocaml-sbom,
ocaml-slack, ocaml-vz, ocaml-zephyr, space, space-block, space-ground,
space-net, space-sim, space-test, space-wire.

- E005: extract send_housekeeping from run_sim to shorten function
- E619: use Fmt.failwith instead of failwith (Fmt.str ...)
- E405/E600: fix test_e2e.mli to export single suite pair with docs

Replace the fixed 7-frame-then-poweroff flight sim with a continuous
loop that propagates ISS orbit via SGP4 and streams real lat/lon/alt/velocity
telemetry interleaved with drifting sensor readings, health, and EVR frames.

Expose gsto (Greenwich Sidereal Time at epoch) from Sgp4.state so
consumers can call to_geodetic without replicating the GMST computation.

Decouple the ground station from the VMM relay following Xen dom0
disaggregation principles. The VMM now creates server sockets for
P0 IPC, P1 IPC, and ground, with QEMU connecting as client. A new
space-ground package provides a standalone web dashboard that connects
to the ground socket and streams frames via SSE to a Tailwind CSS UI.

Also adds the space-sim P0 flight simulator package with diverse frame
types (TM, HEALTH, EVR, ERROR) to exercise the ground dashboard.