fix: follow-ups from the post-merge reviews of #6221, #6227, #6230 and #6239 (#6250)

* fix: follow-ups from the post-merge reviews of #6221, #6227, #6230 and #6239

Six defects the automated reviews found after those PRs merged. Each is
verified rather than taken on trust — two by experiment, the rest by
reading the merged code.

**Import restore never wrote an empty local value** (#6227). GORM builds
the assignment map from the struct passed to Assign and drops zero-valued
fields, so `Assign(model.Setting{Value: ""})` produced an empty Updates
and the imported row survived. Empty is the normal state: UpdateAllSetting
writes a row for every AllSetting field including the blank ones. That is
exactly the case the PR existed for — a destination with no certificate
inheriting the source machine's path. Confirmed with a throwaway test
before changing anything: the value stayed "IMPORTED". Now uses
saveSetting, which is not zero-filtered.

**Import destroyed node mTLS material** (#6227). The "no local row means
the default applied, so drop the import" branch fires for the five
nodeMtls* keys, which are minted on demand and deliberately absent from
AllSetting, so a fresh install has no row for them. Reinstall-then-restore
therefore deleted the CA certificate and its private key — and the backup
was the only copy, since neither is surfaced in the UI or the export.
Those keys are now kept.

**The clients-list enable toggle wiped renewal state** (#6239, #6238).
setEnable hand-builds the update payload and carried reset but not
resetDay or resetMax, so one click on the switch turned calendar mode off
and lifted the renewal cap permanently. The form-modal tests could not
catch it because that path does send both fields.

**"Delete depleted clients" deleted calendar clients** (#6239). The
predicate read `reset = 0` as "does not auto-renew", which is exactly the
calendar shape, in two places. Both now share one constant that also
requires `reset_day = 0`.

**Allowlist validation and parsing disagreed** (#6230). Save used net,
scan used netip, and they differ: `198.51.100.0/024` saves without
complaint and is silently dropped at scan — the failure the PR set out to
remove. Verified by running both parsers. An IPv4-mapped prefix parsed but
could never match, because contains() unmaps the query while the prefix
stayed 128-bit; it is unmapped at parse now. A test asserts the two
acceptance sets agree.

**A comment stated the opposite of the truth** (#6221). GetInbounds has no
enable filter, so a node reports a disabled inbound normally; the row in
that bug report was missing only because it was never delivered. Reworded
to the real invariant.

Also trims two comment blocks in ip_limit_allowlist.go to the repo's
two-line maximum.

Not included: the reviewer's suggestion to lift the node hand-off out of
`if inbound.Enable` in AddInbound. It is the right root-cause fix, but it
changes delivery behaviour on multi-node deployments and belongs in its
own change with its own testing, not in a cleanup batch.

One reported finding is not real: BulkCreate does call
validateClientResetDay, validateClientResetMax and
validateClientTrafficReset — verified in the merged tree.

* fix(netsafe): wrap both errors so errorlint passes

Unrelated to this PR's subject and in a file it does not otherwise touch.
It is here only because CI lints the merge result, and `main` has been red
since #6242 landed: `fmt.Errorf("%w; %v", ...)` wraps the first error and
formats the second, which errorlint rejects. Go 1.20 allows more than one
%w, so both are wrapped now and `errors.Is` works against either.

internal/web/service/client_bulk.go

@@ -1336,7 +1336,7 @@ func (s *ClientService) BulkCreate(inboundSvc *InboundService, payloads []Client
 func (s *ClientService) DelDepleted(inboundSvc *InboundService) (int, bool, error) {
 	db := database.GetDB()
 	now := time.Now().UnixMilli()
-	depletedClause := "reset = 0 and ((total > 0 and up + down >= total) or (expiry_time > 0 and expiry_time <= ?))"
+	depletedClause := depletedClientsClause
 
 	var rows []xray.ClientTraffic
 	if err := db.Where(depletedClause, now).Find(&rows).Error; err != nil {

internal/web/service/depleted_calendar_test.go

@@ -0,0 +1,17 @@
+package service
+
+import (
+	"strings"
+	"testing"
+)
+
+// A calendar client has reset = 0, so the old predicate called it depleted at all
+// times and the operator's purge deleted it along with its traffic row (#6239).
+func TestDepletedClauseExcludesCalendarClients(t *testing.T) {
+	if !strings.Contains(depletedClientsClause, "reset_day = 0") {
+		t.Fatalf("predicate ignores reset_day, so a calendar client would be purged: %q", depletedClientsClause)
+	}
+	if !strings.Contains(depletedClientsClause, "reset = 0") {
+		t.Fatalf("predicate no longer protects interval clients: %q", depletedClientsClause)
+	}
+}

internal/web/service/import_host_settings_test.go

@@ -70,16 +70,15 @@ func TestImportKeepsHostBoundSettings(t *testing.T) {
 	}
 }
 
-// The destination usually has no row at all for the certificate paths and the
-// node identity — the built-in default applies. The imported row must go, or
-// the panel quietly adopts the source machine's certificate path.
+// A certificate path this machine never set must not be inherited from the
+// source. Lazily minted material is the opposite case and is covered below.
 func TestImportDropsHostBoundSettingsThisMachineNeverHad(t *testing.T) {
 	setupConflictDB(t)
 	db := database.GetDB()
 
 	kept := captureHostBoundSettings()
 
-	for _, key := range []string{"webCertFile", "subCertFile", "nodeMtlsClientCertPem"} {
+	for _, key := range []string{"webCertFile", "subCertFile"} {
 		if err := db.Create(&model.Setting{Key: key, Value: "from-imported-file"}).Error; err != nil {
 			t.Fatalf("seed imported %s: %v", key, err)
 		}
@@ -87,7 +86,7 @@ func TestImportDropsHostBoundSettingsThisMachineNeverHad(t *testing.T) {
 
 	restoreHostBoundSettings(kept)
 
-	for _, key := range []string{"webCertFile", "subCertFile", "nodeMtlsClientCertPem"} {
+	for _, key := range []string{"webCertFile", "subCertFile"} {
 		var count int64
 		if err := db.Model(&model.Setting{}).Where("key = ?", key).Count(&count).Error; err != nil {
 			t.Fatal(err)
@@ -97,3 +96,54 @@ func TestImportDropsHostBoundSettingsThisMachineNeverHad(t *testing.T) {
 		}
 	}
 }
+
+// Node mTLS material is minted on demand, so a fresh install has no row and the
+// imported copy is the only one there is — including the CA private key (#6227).
+func TestImportKeepsLazilyMintedMaterialThisMachineNeverHad(t *testing.T) {
+	setupConflictDB(t)
+	db := database.GetDB()
+
+	kept := captureHostBoundSettings()
+
+	for _, key := range []string{"nodeMtlsCaCertPem", "nodeMtlsCaKeyPem", "nodeMtlsClientCertPem", "nodeMtlsClientKeyPem", "nodeMtlsClientCAPem"} {
+		if err := db.Create(&model.Setting{Key: key, Value: "from-imported-file"}).Error; err != nil {
+			t.Fatalf("seed imported %s: %v", key, err)
+		}
+	}
+
+	restoreHostBoundSettings(kept)
+
+	for _, key := range []string{"nodeMtlsCaCertPem", "nodeMtlsCaKeyPem", "nodeMtlsClientCertPem", "nodeMtlsClientKeyPem", "nodeMtlsClientCAPem"} {
+		var got model.Setting
+		if err := db.Where("key = ?", key).First(&got).Error; err != nil {
+			t.Fatalf("%s was dropped; restoring a backup onto a reinstalled panel would lose it: %v", key, err)
+		}
+	}
+}
+
+// An empty local value is the normal state once Panel Settings has been saved:
+// GORM's Assign(struct) dropped it, so the source machine's path survived.
+func TestImportRestoresEmptyLocalValueOverImported(t *testing.T) {
+	setupConflictDB(t)
+	db := database.GetDB()
+
+	if err := db.Create(&model.Setting{Key: "webCertFile", Value: ""}).Error; err != nil {
+		t.Fatalf("seed local empty: %v", err)
+	}
+	kept := captureHostBoundSettings()
+
+	if err := db.Model(&model.Setting{}).Where("key = ?", "webCertFile").
+		Update("value", "/etc/ssl/source-host.pem").Error; err != nil {
+		t.Fatalf("seed imported: %v", err)
+	}
+
+	restoreHostBoundSettings(kept)
+
+	var got model.Setting
+	if err := db.Where("key = ?", "webCertFile").First(&got).Error; err != nil {
+		t.Fatal(err)
+	}
+	if got.Value != "" {
+		t.Fatalf("webCertFile = %q, want the empty local value back: the panel still points at the source machine's certificate", got.Value)
+	}
+}

internal/web/service/inbound_node.go

@@ -714,9 +714,8 @@ func (s *InboundService) setRemoteTrafficLocked(nodeID int, snap *runtime.Traffi
 		if dirty {
 			continue
 		}
-		// Disabled inbounds are intentionally absent from the node's runtime
-		// snapshot. Their absence is not evidence of deletion; retain the row,
-		// client history and port reservation until an explicit delete occurs.
+		// A node inbound created disabled is never delivered, so its absence from
+		// the snapshot is ambiguous rather than evidence of a node-side delete.
 		if !c.Enable {
 			continue
 		}

internal/web/service/inbound_traffic.go

@@ -21,6 +21,10 @@ import (
 	"gorm.io/gorm/clause"
 )
 
+// A client with a renewal day set auto-renews too, so it must not read as
+// depleted — otherwise the operator's purge deletes it between cycles (#6239).
+const depletedClientsClause = "reset = 0 and reset_day = 0 and ((total > 0 and up + down >= total) or (expiry_time > 0 and expiry_time <= ?))"
+
 func (s *InboundService) AddTraffic(inboundTraffics []*xray.Traffic, clientTraffics []*xray.ClientTraffic) (needRestart bool, clientsDisabled bool, err error) {
 	var disabledNodeIDs []int
 	err = submitTrafficWrite(func() error {
@@ -835,7 +839,7 @@ func (s *InboundService) DelDepletedClients(id int) (err error) {
 		// Collect depleted emails globally — a shared-email row owned by one
 		// inbound depletes every sibling that lists the email.
 		now := time.Now().Unix() * 1000
-		depletedClause := "reset = 0 and ((total > 0 and up + down >= total) or (expiry_time > 0 and expiry_time <= ?))"
+		depletedClause := depletedClientsClause
 		var depletedRows []xray.ClientTraffic
 		if err := tx.Model(xray.ClientTraffic{}).
 			Where(depletedClause, now).

internal/web/service/server.go

@@ -1488,25 +1488,37 @@ func restoreHostBoundSettings(snap hostBoundSnapshot) {
 	if db == nil {
 		return
 	}
+	settingSvc := &SettingService{}
 	for _, key := range hostBoundSettingKeys {
 		if _, had := snap.present[key]; !had {
-			// No row here before the import, so the default applied. Drop the
-			// imported row rather than inherit the source machine's value.
+			// Absent because it is minted on demand, not because a default applied:
+			// the imported copy is the only one that exists, so keep it (#6227).
+			if lazilyMintedSettingKeys[key] {
+				continue
+			}
 			if err := db.Where("key = ?", key).Delete(&model.Setting{}).Error; err != nil {
 				logger.Warningf("Import: could not drop imported setting %q: %v", key, err)
 			}
 			continue
 		}
-		// The imported row may or may not exist; settings are key-value, so an
-		// upsert keyed on the name is the only safe write here.
-		if err := db.Where(model.Setting{Key: key}).
-			Assign(model.Setting{Value: snap.values[key]}).
-			FirstOrCreate(&model.Setting{}).Error; err != nil {
+		// saveSetting rather than Assign(struct): GORM drops zero-valued fields from
+		// the assignment map, so an empty local value never overwrote the import.
+		if err := settingSvc.saveSetting(key, snap.values[key]); err != nil {
 			logger.Warningf("Import: could not restore setting %q for this machine: %v", key, err)
 		}
 	}
 }
 
+// Minted on demand, so a fresh install has no row: dropping the imported copy
+// would destroy the only one that exists, CA private key included.
+var lazilyMintedSettingKeys = map[string]bool{
+	"nodeMtlsCaCertPem":     true,
+	"nodeMtlsCaKeyPem":      true,
+	"nodeMtlsClientCertPem": true,
+	"nodeMtlsClientKeyPem":  true,
+	"nodeMtlsClientCAPem":   true,
+}
+
 func (s *ServerService) ImportDB(file multipart.File, keepHostSettings bool) error {
 	if database.IsPostgres() {
 		return s.importPostgresDB(file, keepHostSettings)