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.

Extract helper functions to reduce long function lengths across cwt, jsonwt,
ltp, matter, mbr, json-logs, and initramfs. Remove redundant find_/make_
prefixes in discovery.ml. Extract nested rm closure to reduce nesting depth.

Wire the service config from build.yml through to pid1:
- Add Content entry type to initramfs for inline data
- Add merge_services, topo_sort_services, codegen_plan to Config
- Build generates per-partition Plan module (OCaml data structure)
and recompiles pid1 with services compiled in — no runtime parsing
- pid1 logs the static service plan on boot

Extract ground station into library and embed in space run:
- New space-ground library with Ground.start (no unix dep, uses eio+ptime)
- space run auto-starts the dashboard as a daemon fiber
- bin/main.ml is now a thin cmdliner wrapper

Also adds log_store for per-partition console log capture.