docs: move SkillOpt-Sleep into the guide; clean docs/sleep; fix guide link

Per maintainer request:
- Remove the internal/scratch docs/sleep/ tree (reports, raw logs, blog run
  JSON, sweep.jsonl) — 23 files — and the root PUBLISHING.md. These were
  working notes, not reference docs.
- Take the dedicated SkillOpt-Sleep content out of the main README (News bullet
  + section) and host it in the rendered guide instead: new section 9 in
  docs/guideline.html (deployment companion, the three plugins, opt-in
  experience replay / dream rollouts) with a sidebar entry.
- Fix the README's opening reference so "Documentation & Reproduction Guide"
  links directly to the rendered GitHub Pages page, not the raw .html source.
- Repoint the now-removed docs/sleep links in the plugin READMEs to the guide
  section.

The plugin code (plugins/, skillopt_sleep/) is unchanged; only docs move.

Co-Authored-By: Claude Opus 4 <noreply@anthropic.com>

plugins/copilot/README.md

@@ -64,4 +64,4 @@ You should see the server info and the five `sleep_*` tools.
   portable of the three integrations (one server → CLI + IDE).
 - The engine and all its controls (gate on/off, multi-rollout, budget,
   preferences, optimizer/target split) are identical across platforms — see
-  [`../../docs/sleep/CONTROLLABLE_DREAMING.md`](../../docs/sleep/CONTROLLABLE_DREAMING.md).
+  [the SkillOpt-Sleep guide section](https://microsoft.github.io/SkillOpt/docs/guideline.html#sleep).