Rework the client READMEs to be accurate and inviting to first-time
visitors, and fill in the gaps where crates and tools had none.
- Rewrite clients/{apple,android,decky} READMEs (features-first, trim
dense internal narrative; drop the stale "one session at a time" /
"renegotiation not implemented" section from the Apple README).
- Add READMEs for clients/{linux,windows,probe}, which had none.
- Add crate READMEs for punktfunk-host, punktfunk-core, pf-driver-proto.
- Add brief READMEs for tools/{loss-harness,latency-probe}.
- Fix packaging/README duplicate "Option B" heading (bootc -> Option C).
- Fix docs-site/README stale docs/ -> design/ reference.
- De-stale packaging/windows/drivers/pf-dualsense README (drop "M0 spike"
/ external-checkout framing; reflect in-tree workspace + shipped +
installer-bundled + multi-pad), keeping the driver-authoring lore.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
