feat: Phase 4 governance/execution slice — PolicyService + ExecutionService

classifyAndGate's decision pipeline moves to core: PolicyService runs the
full gate order (classify + transport escalation, plan-first, syntax,
host-only/host-lxc, VM QGA preflight, dedup, approval-flood, window
routing) over ports.GovernanceStore; ExecutionService records and
dispatches (auto-run via ssh.CommandExecutor + TargetResolver, queue via
ExecutionRecorder) with one converged path for run/docker_exec. Gating
matrix test added (risk x window x declared risk -> outcome); pair
coverage 95.6%.

Bug fix surfaced by the matrix: the flag-space syntax regex was inverted
— it refused valid 'tail -n 3' and missed the actual 'head - n' typo.
Fixed to match dash-space-value only.

Remaining Phase 4 items tracked in the plan: ApprovalService.Decide
convergence, execlog fold, execworker poller. VERSION 0.35.0.

plans/index.md

@@ -22,7 +22,7 @@ went sideways, open an investigation.
 | 2026-08-04 | [Hermes MCP client integration](done/2026-08-04-hermes-mcp-client-integration.md) | Done — deployed |
 | 2026-08-05 | [Agent execution safety: QEMU guest agent gate + host-mutation guard](done/2026-08-05-agent-execution-safety-qemu-guest-agent-gate.md) | Done — implemented (1b9c761) |
 | 2026-08-05 | [Backend evaluation: architecture, security, and reliability improvements](2026-08-05-backend-evaluation-improvements.md) | Done — all three phases (B, D, E) implemented as code (0.28.0–0.29.0), deployed, and hardened via review. Remaining: C (security) and F (performance) backlog. |
-| 2026-08-15 | [Hexagonal architecture — design and phased refactor](2026-08-15-hexagonal-architecture.md) | In Progress — Phases 0–7 shipped; Phase 8 (nomos cleanup) and the Phase 9 coverage gates open |
+| 2026-08-15 | [Hexagonal architecture — design and phased refactor](2026-08-15-hexagonal-architecture.md) | In Progress — Phases 0–7 + governance slice shipped; Phase 8 (nomos cleanup) and Phase 9 remainders open |
 
 ## Done