fix: port the PR #6105 review-round fixes into this fork's own AmneziaWG code

Same 8 findings fixed on upstream-pr/amneziawg, ported here since this
fork's internal/amneziawg + related web/service files predate that PR
branch's own fix-up commits:

1. hostRulesFingerprint now folds in a peer's IPv4 whenever
   ForwardedPorts is set, not only when RouteThroughXray is on, so a
   re-IP forces the bounce needed to move the DNAT rule too.
2. ValidateConfigValue (new, params.go) rejects control characters in
   server/client keys, email and I1 at save time; sanitizeConfigValue
   strips them defensively at .conf-render time.
3. checkForwardedPortsConflict now scopes to node_id IS NULL and takes
   a pre-loaded portConflictContext (loadPortConflictContext), so a
   port used only on another node isn't a false collision and an
   inbound with N clients costs one query instead of N.
4. PostDown commands are now best-effort (appendOrTrue) so an external
   firewall flush can't abort the rest of the teardown chain.
5. The "ip rule list | grep -q" existence check now uses
   grep -c >/dev/null, avoiding a pipefail/SIGPIPE false negative that
   could re-add a duplicate rule.
6. route_egress.go's stale "always present, no opt-in" comment
   corrected to describe the real RouteThroughXray-gated behavior.
   (This fork's genAmneziaWGLink already emits vpn://, and there's no
   upstream-facing docs page here, so neither needed the PR branch's
   Finding 6 docs/link-format changes.)
7. install.sh: Arch's ndppd install uses pacman -Sy, not -Syu, matching
   every other pacman call in the script; should_install_amneziawg
   short-circuits to yes when awg is already installed, so `x-ui
   update` doesn't re-prompt -- this fork's own opt-out-by-default
   philosophy for should_install_amneziawg is unchanged, only the
   redundant-reprompt behavior is fixed.
8. CollectTraffic checks pointer identity before writing back a
   traffic-counter baseline, so a concurrent restart's freshly-reset
   (empty) baseline can't be clobbered by stale pre-restart counters.
   sweepOrphansLocked no longer permanently disables itself on a
   transient os.ReadDir failure.

go build/vet/test and frontend typecheck/lint/build/vitest all pass.

internal/web/service/inbound_amneziawg_test.go

@@ -11,21 +11,25 @@ import (
 func TestCheckForwardedPortsConflict_EmptySpecNoConflict(t *testing.T) {
 	setupConflictDB(t)
 	svc := &InboundService{}
-	hit, err := svc.checkForwardedPortsConflict("")
-	if err != nil || hit != "" {
-		t.Fatalf("an empty spec must never conflict; got hit=%q err=%v", hit, err)
+	ctx, err := svc.loadPortConflictContext()
+	if err != nil {
+		t.Fatalf("loadPortConflictContext: %v", err)
+	}
+	if hit := svc.checkForwardedPortsConflict(ctx, ""); hit != "" {
+		t.Fatalf("an empty spec must never conflict; got hit=%q", hit)
 	}
 }
 
 func TestCheckForwardedPortsConflict_CollidesWithPanelPort(t *testing.T) {
 	setupConflictDB(t)
 	svc := &InboundService{}
+	ctx, err := svc.loadPortConflictContext()
+	if err != nil {
+		t.Fatalf("loadPortConflictContext: %v", err)
+	}
 	// getString falls back to defaultValueMap's "webPort": "2053" on a fresh
 	// DB with no explicit setting row.
-	hit, err := svc.checkForwardedPortsConflict("2053")
-	if err != nil {
-		t.Fatalf("checkForwardedPortsConflict: %v", err)
-	}
+	hit := svc.checkForwardedPortsConflict(ctx, "2053")
 	if !strings.Contains(hit, "panel") {
 		t.Fatalf("expected a collision naming the panel's own port, got %q", hit)
 	}
@@ -36,10 +40,11 @@ func TestCheckForwardedPortsConflict_CollidesWithEnabledInboundPort(t *testing.T
 	seedInboundConflict(t, "vless-8080", "0.0.0.0", 8080, model.VLESS, `{"network":"tcp"}`, `{}`)
 
 	svc := &InboundService{}
-	hit, err := svc.checkForwardedPortsConflict("8000-8100")
+	ctx, err := svc.loadPortConflictContext()
 	if err != nil {
-		t.Fatalf("checkForwardedPortsConflict: %v", err)
+		t.Fatalf("loadPortConflictContext: %v", err)
 	}
+	hit := svc.checkForwardedPortsConflict(ctx, "8000-8100")
 	if !strings.Contains(hit, "vless-8080") {
 		t.Fatalf("expected a collision naming the colliding inbound, got %q", hit)
 	}
@@ -53,9 +58,12 @@ func TestCheckForwardedPortsConflict_IgnoresDisabledInboundPort(t *testing.T) {
 	}
 
 	svc := &InboundService{}
-	hit, err := svc.checkForwardedPortsConflict("8080")
-	if err != nil || hit != "" {
-		t.Fatalf("a disabled inbound's port must not be reserved; got hit=%q err=%v", hit, err)
+	ctx, err := svc.loadPortConflictContext()
+	if err != nil {
+		t.Fatalf("loadPortConflictContext: %v", err)
+	}
+	if hit := svc.checkForwardedPortsConflict(ctx, "8080"); hit != "" {
+		t.Fatalf("a disabled inbound's port must not be reserved; got hit=%q", hit)
 	}
 }
 
@@ -64,9 +72,32 @@ func TestCheckForwardedPortsConflict_NoCollisionWhenPortsDontOverlap(t *testing.
 	seedInboundConflict(t, "vless-8080", "0.0.0.0", 8080, model.VLESS, `{"network":"tcp"}`, `{}`)
 
 	svc := &InboundService{}
-	hit, err := svc.checkForwardedPortsConflict("9000-9100")
-	if err != nil || hit != "" {
-		t.Fatalf("unrelated ports must not conflict; got hit=%q err=%v", hit, err)
+	ctx, err := svc.loadPortConflictContext()
+	if err != nil {
+		t.Fatalf("loadPortConflictContext: %v", err)
+	}
+	if hit := svc.checkForwardedPortsConflict(ctx, "9000-9100"); hit != "" {
+		t.Fatalf("unrelated ports must not conflict; got hit=%q", hit)
+	}
+}
+
+// A port-forward spec matching a port used only by an inbound hosted on a
+// DIFFERENT node must not conflict: that inbound's DNAT/listen socket lives
+// on the node's own host, never on this panel's, so there is nothing here
+// for the forwarded port to actually collide with. Mirrors
+// TestCheckPortConflict_NodeScope's own reasoning for the general port-
+// conflict check.
+func TestCheckForwardedPortsConflict_IgnoresPortOnDifferentNode(t *testing.T) {
+	setupConflictDB(t)
+	seedInboundConflictNode(t, "node1-8080", "0.0.0.0", 8080, model.VLESS, `{"network":"tcp"}`, `{}`, new(1))
+
+	svc := &InboundService{}
+	ctx, err := svc.loadPortConflictContext()
+	if err != nil {
+		t.Fatalf("loadPortConflictContext: %v", err)
+	}
+	if hit := svc.checkForwardedPortsConflict(ctx, "8080"); hit != "" {
+		t.Fatalf("a port used only on a different node must not conflict; got hit=%q", hit)
 	}
 }