feat(sleep): SkillOpt-Sleep plugin update (preview) — engine robustness + scheduling

Updates the SkillOpt-Sleep plugin on top of the current main. User-facing and
engine improvements since the initial drop:

* Command renamed /sleep -> /skillopt-sleep across Claude Code + Codex shells;
  refreshed plugin READMEs and install scripts.
* Built-in scheduling (skillopt_sleep/scheduler.py + __main__): schedule /
  unschedule the nightly cycle without external cron wiring.
* Backend robustness: bounded retry with backoff (no more silent empty-string
  on transient 429/timeout), content-filter-safe rollout prompt, an
  output-contract guardrail that rejects edits violating the task's required
  format, and a per-sample cache key so repeated dream rollouts are independent
  samples (fixes degenerate single-sample reflection).
* consolidate / rollout / replay: parallel multi-rollout dreaming, gate-mode
  controls, TaskRecord.system framing field.

Scope: this commit ships only the plugin engine + shells. Research/benchmark
harnesses and their data are intentionally not included; the public package
has no dependency on them (the one research-evaluator import is now guarded).
Marked as an early preview in the README; we'll keep iterating.

99/99 unit tests pass.

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

plugins/codex/README.md

@@ -23,7 +23,7 @@ three, plus a shared runner.
 ```bash
 git clone <repo-url> SkillOpt-Sleep
 cd SkillOpt-Sleep
-bash plugins/codex/install.sh          # installs the /sleep prompt + skill
+bash plugins/codex/install.sh          # installs the /skillopt-sleep prompt + skill
 export SKILLOPT_SLEEP_REPO="$(pwd)"    # so the runner is found from anywhere
 ```
 
@@ -32,10 +32,10 @@ Requires Python ≥ 3.10 and the `codex` CLI on PATH.
 ## Use
 
 ```text
-/sleep status      # what's happened
-/sleep dry-run     # safe preview, stages nothing
-/sleep run         # full cycle, stages a reviewed proposal (no live edits)
-/sleep adopt       # apply the staged proposal (with backup)
+/skillopt-sleep status      # what's happened
+/skillopt-sleep dry-run     # safe preview, stages nothing
+/skillopt-sleep run         # full cycle, stages a reviewed proposal (no live edits)
+/skillopt-sleep adopt       # apply the staged proposal (with backup)
 ```
 
 Or call the engine directly:

plugins/codex/install.sh

@@ -9,10 +9,10 @@ AGENTS_SKILLS="${HOME}/.agents/skills"
 
 echo "[install] repo: $REPO_ROOT"
 
-# 1) custom /sleep prompt
+# 1) custom /skillopt-sleep prompt
 mkdir -p "$CODEX_HOME/prompts"
-cp "$REPO_ROOT/plugins/codex/prompts/sleep.md" "$CODEX_HOME/prompts/sleep.md"
-echo "[install] /sleep prompt   -> $CODEX_HOME/prompts/sleep.md"
+cp "$REPO_ROOT/plugins/codex/prompts/skillopt-sleep.md" "$CODEX_HOME/prompts/skillopt-sleep.md"
+echo "[install] /skillopt-sleep prompt   -> $CODEX_HOME/prompts/skillopt-sleep.md"
 
 # 2) user-level skill
 mkdir -p "$AGENTS_SKILLS/skillopt-sleep"
@@ -30,7 +30,7 @@ cat <<EOF
 
   ## SkillOpt-Sleep
   An offline self-improvement cycle is available. To run it:
-  \`bash "$REPO_ROOT/plugins/run-sleep.sh" status\`. Use \`/sleep\` for the guided flow.
+  \`bash "$REPO_ROOT/plugins/run-sleep.sh" status\`. Use \`/skillopt-sleep\` for the guided flow.
 
-Done. Try:  /sleep status
+Done. Try:  /skillopt-sleep status
 EOF

plugins/codex/prompts/skillopt-sleep.md

@@ -1,7 +1,7 @@
-# /sleep — SkillOpt-Sleep for Codex
+# /skillopt-sleep — SkillOpt-Sleep for Codex
 #
-# Custom prompt: copy this file to ~/.codex/prompts/sleep.md and invoke with
-# `/sleep` in the Codex CLI. ($ARGUMENTS is the text after /sleep.)
+# Custom prompt: copy this file to ~/.codex/prompts/skillopt-sleep.md and invoke with
+# `/skillopt-sleep` in the Codex CLI. ($ARGUMENTS is the text after /skillopt-sleep.)
 
 Run the SkillOpt-Sleep offline self-evolution cycle. Action: $ARGUMENTS
 (empty → "status").

plugins/codex/skills/skillopt-sleep/SKILL.md

@@ -34,7 +34,7 @@ for real improvement on the user's own Codex budget (default `mock` = no spend).
 2. For `run`/`dry-run`: read the staged `report.md` it prints and show the user
    the held-out baseline → candidate score and the exact proposed edits.
 3. `run` only **stages** a proposal under `<project>/.skillopt-sleep/staging/`;
-   nothing live changes until `adopt`. Offer `/sleep adopt`.
+   nothing live changes until `adopt`. Offer `/skillopt-sleep adopt`.
 4. Never hand-edit the user's `AGENTS.md` / skills yourself — only `adopt` does,
    and it backs up first.