Add read-only Lattice topology provenance

[mgazza]

Summary

• add default-off, read-only ingestion of the gateway's retained Lattice topology
• merge provider documents by authority, recency, and stable input order
• preserve provider-local capability refs in a provenance sidecar after merged refs are reminted
• expose GatewayMQTT.lattice_source_ref(...) as the future intent-dispatch seam
• support current 0.2 fragments and the proposed 0.3 topology family

This PR does not publish /control, alter the planner, or write to inverter hardware.

Safety

• feature flag defaults off (lattice_projection_enable)
• malformed/stale/reused-version documents preserve the last known-good snapshot
• node/capability tombstones remove stale provenance
• exact-rank live/tombstone conflicts have deterministic first-input behavior

Verification

• python3 apps/predbat/tests/test_lattice_topology.py — 11/11 passed
• Python syntax compilation passed
• Ruff, Black, CSpell, whitespace hooks passed
• GitNexus final change scope: LOW for the tie correction, no affected execution flows

Tracking

• Canonical implementation epic: Predictive-Cloud-Ltd/predbat-saas-infra#466
• Lattice 0.3 intent/result proposal: feat: Lattice 0.3 schedule intent and durable control results Predictive-Cloud-Ltd/lattice-spec#35
• Follows the initial SaaS/BatPred Lattice work in Lattice: read-only device map + producers + authority-ranked merge & resolve (conformance-pinned) #4147