docs(codex): wire the compaction hook into README and codex-tools, add drift-cure footer

README gains the hook install step for Codex users (hooks.json merge,
one-time trust prompt, --dangerously-bypass-hook-trust for headless
automation). codex-tools.md aligns its claims with the mechanism — the
dispatch rules bind every spawn, the printed hints appear at scripted
boundaries, and the hook covers post-compaction re-grounding — and adds
a section telling controllers compaction sheds these instructions and
to treat every printed hint as authoritative.

The hints file gains a drift-cure footer both scripts print after the
role line: in the instrumented run that broke post-compaction,
reprinted hints alone did not heal the already-broken dispatch pattern
across three subsequent boundaries — recovery text must name the drift
and prescribe the re-read.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

skills/using-superpowers/references/codex-dispatch.hints

@@ -5,6 +5,10 @@
 # Model names track Codex's spawn_agent allowlist (currently gpt-5.6-sol
 # and gpt-5.6-terra) — update this file when the allowlist changes.
 # Format: <role>: <line printed verbatim>
+# The footer line prints after every role line: prevention alone does not
+# cure drift — in instrumented runs, reprinted hints did not heal an
+# already-broken dispatch pattern until the text named the drift directly.
+footer: If any spawn this session omitted these params or used fork_turns "all", you have drifted — re-read references/codex-tools.md before dispatching again.
 implementer: dispatch (spawn_agent): fork_turns=none model=gpt-5.6-terra reasoning_effort=high
 task-review: dispatch (spawn_agent): fork_turns=none model=gpt-5.6-terra reasoning_effort=high
 fix-review: dispatch (spawn_agent): fork_turns=none model=gpt-5.6-terra reasoning_effort=medium