03 — Remove Legacy Planner v2 from the Authoritative Path

Native fact planner replaces plan_v2; every authoritative caller repointed.

• fn_qt001_plan_v5(collection): native per-collection FACT planner (src_rows, existing_births, expected_delta, collision_count, unresolvable, divergence, apply_safe) computed from the governed identity/policy resolvers (fn_birth_policy_decision, fn_birth_resolve_identity) + birth_registry. Facts only; apply AUTHORITY is downstream (rule-engine + readiness + signoff + capability), never this function's flags. NO reference to plan_v2.
• fn_qt001_plan_all_v5(): iterates plan_v5 (no plan_all/plan_v2).
• Repointed (CREATE OR REPLACE, FIX4 bodies captured for rollback): writer fn_dot_birth_qt001_apply (first stmt now plan_v5; execute path checks legacy guard + readiness v8 + fingerprint v5 + signoff v5); driver sp_dot_birth_qt001_apply (plan_v5; batch/runaway from qt001_runtime_config, no magic literals); fn_qt001_refresh_plan_snapshot→plan_all_v5; builder fn_qt001_build_plan_registry→fingerprint v5 + signals v5 + blocked_reason v5, NULL-strict checksum, content-addressed plan_id, pg_advisory_xact_lock serialization, rejects invalid fingerprint; tier wrapper fn_qt001_machine_tier→v5; fn_qt001_machine_blocked_reason→v5 inputs.

Guards: v_qt001_no_legacy_planner_guard (roots_reaching_planner_v2=0, roots_reaching_legacy=0, pass=true), v_qt001_planner_v2_sentinel_only_guard (plan_v2 exists, classified legacy, roots_reaching=0, pass=true), v_qt001_writer_authoritative_repoint_status_v5 (writer uses plan_v5/readiness_v8/fingerprint_v5/signoff_v5; driver uses plan_v5; pass=true). plan_v2 retained as frozen sentinel (not dropped, unreachable). Tier dist unchanged vs FIX4: TIER2 7 / TIER3 6 / BLOCKED 6 / INELIGIBLE 55 / TIER1 0.