fix(node): stop client edits from tearing down node inbounds and harden reconcile fingerprints

A client save on the master always stamped a fresh updated_at, marked
the node dirty, and let the 5s sync push a full inbounds/update to the
node, where applying it removes and re-adds the Xray handler - killing
live traffic on every edit, including no-op saves (open the editor,
click Save). Nodes stayed online with Xray running while forwarding
nothing until a manual Xray restart.

- No-op client saves preserve the client's updated_at and return before
  any DB write, runtime RPC, or node dirty mark when the effective
  settings did not change.
- Successful per-client add/update/delete pushes advance the node's
  reconcile-skip fingerprint only when the recorded fingerprint proves
  the node held the exact pre-edit payload and every push in the edit
  succeeded (Remote.AdvancePushedInbound). Anything unproven keeps the
  stale fingerprint so the dirty reconcile still sends the full inbound.
  Unconditional stamping would certify folded bulk changes (threshold,
  flow change, offline edit) or partially failed batches as delivered:
  a folded 41->6 bulk delete followed by one live edit left the node
  permanently serving all 41 clients in end-to-end testing, with the
  snapshot adoption then resurrecting the deleted clients on the master.
- DeleteUser treats only an envelope-level not-found as already deleted;
  an HTTP 404 from an old node build without the detach endpoint
  surfaces as an error instead of certifying an undelivered delete.
  cacheDel drops the fingerprint alongside the id cache so DelInbound
  and tag renames leave no stale skip entry.
- Adopting the node's own settings serialization into the master row now
  also stamps the fingerprint (RecordAdoptedInbound). Without it the
  serialization round-trip invalidated the fingerprint one sync tick
  after every push, so each edit degraded back to a full teardown push.
- UpdateInboundClient applies the Shadowsocks method normalization
  before the no-op comparison (real method changes bump updated_at, SS
  no-op edits are detected) and syncs the generated subId into the
  pushed client so the node cannot mint a different one.

Verified with a two-panel docker deployment: no-op saves produce zero
node requests, real edits send one lightweight clients/update RPC with
zero full inbound updates and zero handler teardowns, and folded bulk
deletes still converge.

Based on PR #5778 by @rqzbeh.

Closes #5764
Closes #5771

internal/web/service/client_inbound_apply.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"maps"
 	"strings"
 	"time"
 
@@ -18,6 +19,28 @@ import (
 	"gorm.io/gorm"
 )
 
+func sameClientConfigExceptUpdatedAt(a, b map[string]any) bool {
+	aa := maps.Clone(a)
+	bb := maps.Clone(b)
+	delete(aa, "updated_at")
+	delete(bb, "updated_at")
+	an, aerr := json.Marshal(aa)
+	bn, berr := json.Marshal(bb)
+	return aerr == nil && berr == nil && string(an) == string(bn)
+}
+
+// advancePushedInbound advances the node's reconcile-skip fingerprint from the
+// pre-edit settings to the saved ones after every per-client push succeeded.
+func advancePushedInbound(rt runtime.Runtime, prevSettings string, ib *model.Inbound) {
+	rem, ok := rt.(*runtime.Remote)
+	if !ok {
+		return
+	}
+	prev := *ib
+	prev.Settings = prevSettings
+	rem.AdvancePushedInbound(&prev, ib)
+}
+
 // delInboundClients removes several clients from a single inbound in one pass:
 // one settings rewrite, one runtime sweep, one Save and one SyncInbound for the
 // whole batch, instead of repeating the full per-client cycle. It mirrors the
@@ -89,6 +112,7 @@ func (s *ClientService) delInboundClients(inboundSvc *InboundService, inboundId
 	if err != nil {
 		return false, err
 	}
+	prevSettings := oldInbound.Settings
 	oldInbound.Settings = string(newSettings)
 
 	var sharedSet map[string]bool
@@ -185,6 +209,7 @@ func (s *ClientService) delInboundClients(inboundSvc *InboundService, inboundId
 
 	// Apply runtime deletes after commit — outside the serialized writer so a
 	// slow node call can't stall traffic accounting.
+	nodePushFailed := false
 	for _, t := range targets {
 		if len(t.email) == 0 {
 			continue
@@ -203,9 +228,13 @@ func (s *ClientService) delInboundClients(inboundSvc *InboundService, inboundId
 		} else if nodePush {
 			if err1 := nodeRt.DeleteUser(context.Background(), oldInbound, t.email); err1 != nil {
 				logger.Warning("Error in deleting client on", nodeRt.Name(), ":", err1)
+				nodePushFailed = true
 			}
 		}
 	}
+	if nodePush && !nodePushFailed {
+		advancePushedInbound(nodeRt, prevSettings, oldInbound)
+	}
 
 	return needRestart, nil
 }
@@ -349,6 +378,7 @@ func (s *ClientService) addInboundClient(inboundSvc *InboundService, data *model
 		return false, err
 	}
 
+	prevSettings := oldInbound.Settings
 	oldInbound.Settings = string(newSettings)
 
 	needRestart := false
@@ -441,6 +471,9 @@ func (s *ClientService) addInboundClient(inboundSvc *InboundService, data *model
 				}
 			}
 		}
+		if push {
+			advancePushedInbound(rt, prevSettings, oldInbound)
+		}
 	}
 
 	return needRestart, nil
@@ -565,21 +598,25 @@ func (s *ClientService) UpdateInboundClient(inboundSvc *InboundService, data *mo
 	settingsClients, _ := oldSettings["clients"].([]any)
 	var preservedCreated any
 	var preservedSubID string
+	var oldClientMap map[string]any
 	if clientIndex >= 0 && clientIndex < len(settingsClients) {
 		if oldMap, ok := settingsClients[clientIndex].(map[string]any); ok {
+			oldClientMap = oldMap
 			if v, ok2 := oldMap["created_at"]; ok2 {
 				preservedCreated = v
 			}
 			preservedSubID, _ = oldMap["subId"].(string)
 		}
 	}
+	if oldInbound.Protocol == model.Shadowsocks {
+		applyShadowsocksClientMethod(interfaceClients, oldSettings)
+	}
 	if len(interfaceClients) > 0 {
 		if newMap, ok := interfaceClients[0].(map[string]any); ok {
 			if preservedCreated == nil {
 				preservedCreated = time.Now().Unix() * 1000
 			}
 			newMap["created_at"] = preservedCreated
-			newMap["updated_at"] = time.Now().Unix() * 1000
 			newSub, _ := newMap["subId"].(string)
 			if strings.TrimSpace(newSub) == "" {
 				if strings.TrimSpace(preservedSubID) != "" {
@@ -588,6 +625,9 @@ func (s *ClientService) UpdateInboundClient(inboundSvc *InboundService, data *mo
 					newMap["subId"] = random.NumLower(16)
 				}
 			}
+			if v, ok2 := newMap["subId"].(string); ok2 {
+				clients[0].SubID = v
+			}
 			if oldInbound.Protocol == model.WireGuard {
 				newMap["privateKey"] = clients[0].PrivateKey
 				newMap["publicKey"] = clients[0].PublicKey
@@ -599,12 +639,18 @@ func (s *ClientService) UpdateInboundClient(inboundSvc *InboundService, data *mo
 					newMap["keepAlive"] = clients[0].KeepAlive
 				}
 			}
+			if oldClientMap != nil && sameClientConfigExceptUpdatedAt(oldClientMap, newMap) {
+				if v, ok2 := oldClientMap["updated_at"]; ok2 {
+					newMap["updated_at"] = v
+				} else {
+					delete(newMap, "updated_at")
+				}
+			} else {
+				newMap["updated_at"] = time.Now().Unix() * 1000
+			}
 			interfaceClients[0] = newMap
 		}
 	}
-	if oldInbound.Protocol == model.Shadowsocks {
-		applyShadowsocksClientMethod(interfaceClients, oldSettings)
-	}
 	settingsClients[clientIndex] = interfaceClients[0]
 	oldSettings["clients"] = settingsClients
 
@@ -630,6 +676,11 @@ func (s *ClientService) UpdateInboundClient(inboundSvc *InboundService, data *mo
 		return false, err
 	}
 
+	if string(newSettings) == oldInbound.Settings {
+		return false, nil
+	}
+
+	prevSettings := oldInbound.Settings
 	oldInbound.Settings = string(newSettings)
 
 	needRestart := false
@@ -768,6 +819,8 @@ func (s *ClientService) UpdateInboundClient(inboundSvc *InboundService, data *mo
 		} else if push {
 			if err1 := rt.UpdateUser(context.Background(), oldInbound, oldEmail, clients[0]); err1 != nil {
 				logger.Warning("Error in updating client on", rt.Name(), ":", err1)
+			} else {
+				advancePushedInbound(rt, prevSettings, oldInbound)
 			}
 		}
 	} else {
@@ -828,6 +881,7 @@ func (s *ClientService) DelInboundClientByEmail(inboundSvc *InboundService, inbo
 		return false, err
 	}
 
+	prevSettings := oldInbound.Settings
 	oldInbound.Settings = string(newSettings)
 
 	emailShared, err := inboundSvc.emailUsedByOtherInbounds(email, inboundId)
@@ -922,6 +976,8 @@ func (s *ClientService) DelInboundClientByEmail(inboundSvc *InboundService, inbo
 			if push {
 				if err1 := rt.DeleteUser(context.Background(), oldInbound, email); err1 != nil {
 					logger.Warning("Error in deleting client on", rt.Name(), ":", err1)
+				} else {
+					advancePushedInbound(rt, prevSettings, oldInbound)
 				}
 			}
 		}