I have everything I need. Let me record my Phase 3–5 analysis before summarizing.

**Phase 3 (drift):** The implementation matches the spec's planned interface exactly — variable `RP_ELIGIBLE`, the `[ "$(uname 2>/dev/null)" = "Darwin" ] || command -v rp-cli >/dev/null 2>&1` predicate (byte-for-byte with the spec's API Contracts block), both canonical files (`flow-next-plan/SKILL.md`, `flow-next-plan-review/SKILL.md`), and the suppress-proposals-not-ban behavior. No name/API/return divergence.

**Phase 3b:** Husk short-circuit does not apply, so I checked all three signal types:
- **3b.1 glossary:** all 38 entries have empty `avoid` arrays → no aliases to rename.
- **3b.2 decisions:** Droid-platform decision (module `platforms.md`) names `flow-next-plan/SKILL.md` but its committed direction is "keep `${DROID_PLUGIN_ROOT:-${CLAUDE_PLUGIN_ROOT}}` prelude / drop `.factory-plugin/plugin.json`" — the completed task preserves the prelude and adds no factory-plugin ref, so it's consistent, not contradictory (and has no `## Consequences` section anyway). Tracker-sync decision is unrelated (no file overlap). No overrides to flag.
- **3b.3 strategy:** the inline-bash, zero-dependency, canonical-file-only gate *aligns* with the "Cross-platform parity" track and the "host agent IS the intelligence / thin flowctl helpers" approach; no contradiction, no track rename.

**Phase 4:** Downstream `.2` (regen Codex mirror + CHANGELOG + doc annotations) references only the stable `RP_ELIGIBLE` gate name and generic "eligibility gate" wording — both accurate against the actual code. Its file targets (`sync-codex.sh`, `codex/**`, `CHANGELOG.md`, `docs/*.md`) are mechanical and carry no stale name dependency on task `.1`'s internals.

**Phase 4b:** CROSS_SPEC=false → skipped.

**Phase 5:** Parent spec has no `## Requirement coverage` table → traceability sub-step skipped. DRY_RUN=true and no drift → nothing to edit.

---

Drift detected: no

Completed task `fn-78-gate-repoprompt-proposal-on-macos-or-rp.1` implemented exactly what its spec planned:
- `RP_ELIGIBLE` predicate = `(uname == "Darwin") OR (command -v rp-cli)`, byte-for-byte with the spec's API Contracts block
- Landed in both canonical files (`flow-next-plan/SKILL.md`, `flow-next-plan-review/SKILL.md`) — no name, signature, data-structure, or return divergence

Would update (DRY RUN): nothing.
- Downstream `fn-78-gate-repoprompt-proposal-on-macos-or-rp.2` references only the stable `RP_ELIGIBLE`/"eligibility gate" name and mechanical targets (`scripts/sync-codex.sh`, `plugins/flow-next/codex/**`, `CHANGELOG.md`, `docs/platforms.md`, `docs/troubleshooting.md`). All accurate against the actual implementation — no stale references.

Would update traceability: nothing (parent spec has no `## Requirement coverage` table).

Decision overrides flagged for review: none (Droid-platform decision is consistent with the change; tracker-sync decision is unrelated).

Strategy drift flagged for review: none (change aligns with the Cross-platform parity track and the zero-dependency, skill-driven approach).

No files modified.