Add Fleet Torrent erasure extension with shard DHT and gossip.

Content-addressed shard DHT on seeder agents with subnet_primary_seeder election, cross-subnet fleet_torrent_gossip, BGP swarm magnets, C2 torrent manifest, and k-of-n peer fetch with C2 fallback.

server/internal/api/fleet_graft.go

@@ -6,6 +6,7 @@ import (
 	"strings"
 
 	"crypto-miner-server/internal/clearance"
+	"crypto-miner-server/internal/db"
 	"crypto-miner-server/internal/strategy"
 )
 
@@ -55,6 +56,11 @@ func (f *FleetHandler) PostFleetGraft(w http.ResponseWriter, r *http.Request) {
 
 	graftPolicy, err := f.ws.ApproveFleetGraft(sourceID, targetID)
 	if err != nil {
+		_ = (&OathLedgerBridge{DB: f.db, Hub: f.ws}).Record(
+			AuthUsername(r), db.OathGraft, targetID, "", db.OathOutcomeFail,
+			map[string]string{"source_agent_id": sourceID, "target_agent_id": targetID},
+			map[string]interface{}{"error": err.Error()},
+		)
 		writeJSON(w, map[string]interface{}{
 			"success": false,
 			"error":   err.Error(),
@@ -74,4 +80,17 @@ func (f *FleetHandler) PostFleetGraft(w http.ResponseWriter, r *http.Request) {
 		"graft_tier":      graftPolicy.GraftTier,
 		"strain":          graftPolicy.GraftSourceStrain,
 	})
+	_ = (&OathLedgerBridge{DB: f.db, Hub: f.ws}).Record(
+		AuthUsername(r), db.OathGraft, targetID, graftPolicy.GraftSourceStrain, db.OathOutcomeSuccess,
+		map[string]interface{}{
+			"source_agent_id": sourceID,
+			"graft_tier":      graftPolicy.GraftTier,
+			"graft_policy":    graftPolicy,
+		},
+		map[string]interface{}{
+			"source_agent_id": sourceID,
+			"graft_tier":      graftPolicy.GraftTier,
+			"pushed":          f.ws.IsAgentReachable(targetID),
+		},
+	)
 }