feat: integrate sweep-v2 plan review adapter

[robgfl45]

Summary

• default the headless plan-review adapter to the feature-flagged sweep-v2 engine while retaining explicit --engine legacy compatibility
• classify sweep results only from terminal state, immutable snapshot/manifest hashes, exact same-snapshot five-persona sidecars/findings, aggregate evidence hashes, and consolidated findings
• expose generation/hash/persona coverage and copied state/generation evidence paths for cleanup-safe read-back
• update the staged Hermes project-plan-review skill/runbook for five generations, the 180-second outer timeout reserve, subscription telemetry wording, and mandatory re-review after material Drake normalization
• add deterministic false-clean regressions for clean convergence, generation-five material max-reached, missing/malformed/mutated/hash-mismatched/degraded/cancelled evidence, timeout reaping, and legacy behavior

Validation

• python3 -m unittest -v tests/test_adapter.py — 14 passed
• bash plugins/claudex/tests/sweep-v2-test.sh — 60 passed
• bash plugins/claudex/tests/platform-validation.sh — 61 passed
• bash plugins/claudex/tests/smoke-test.sh — 74 passed
• bash plugins/claudex/tests/synthetic-e2e.sh — 23 passed (supplementary legacy E2E; one real Codex subscription-backed review call, no live sweep)
• python3 -m py_compile bin/claudex-plan-review tests/test_adapter.py — passed
• bash -n plugins/claudex/scripts/*.sh plugins/claudex/hooks/*.sh plugins/claudex/tests/*.sh — passed
• git diff --check / git diff dae1202aaca2ad349d2ec70221d23e59a822142b...HEAD --check — passed
• gitleaks protect --staged — no leaks found

Scope / rollout

• exact baseline: dae1202aaca2ad349d2ec70221d23e59a822142b (merged Phase 1 PR Scope Stop hook + start-loop to current session_id (fix multi-session pollution) #4)
• no install, activation, global/live configuration change, or merge performed
• no real live sweep performed; live Phase 2 sweep verification remains a post-merge Drake responsibility

[robgfl45]

Opened against the upstream repository by mistake. Superseded by robgfl45#5.