fix(xhttp): stop injecting scMaxEachPostBytes/scMinPostsIntervalMs defaults (#5141)

The panel seeded xhttp configs with scMaxEachPostBytes=1000000 and
scMinPostsIntervalMs=30 — xray-core''s own defaults — and emitted them
into every generated config and share link. The literal
scMinPostsIntervalMs=30 is a stable DPI fingerprint that Russia''s TSPU
keys on to block connections on mobile networks.

New configs no longer seed these values (empty schema/template defaults,
so xray-core applies its internal defaults). For configs already stored
with the old defaults, the link/subscription builders now drop values
equal to xray-core''s defaults instead of advertising them — covering
panel share links, the raw subscription, and the JSON subscription
without requiring every inbound to be re-saved. Non-default values the
user set deliberately are still emitted.

frontend/src/lib/xray/inbound-link.ts

@@ -59,9 +59,15 @@ function buildXhttpExtra(xhttp: XHttpStreamSettings | undefined): Record<string,
     'uplinkDataKey',
     'scMaxEachPostBytes',
   ] as const;
+  // Values matching xray-core's own defaults stay off the wire — old panels
+  // seeded them into every config and the literal values are a DPI
+  // fingerprint (#5141). Mirrors the sub service's filter.
+  const coreDefaults: Partial<Record<(typeof stringFields)[number], string>> = {
+    scMaxEachPostBytes: '1000000',
+  };
   for (const k of stringFields) {
     const v = xhttp[k];
-    if (typeof v === 'string' && v.length > 0) extra[k] = v;
+    if (typeof v === 'string' && v.length > 0 && v !== coreDefaults[k]) extra[k] = v;
   }
 
   // Headers on the wire are a record; emit them as a map upstream's

frontend/src/lib/xray/outbound-link-parser.ts

@@ -114,7 +114,7 @@ function buildStream(network: string, security: string): Raw {
     case 'xhttp':
       stream.xhttpSettings = {
         path: '/', host: '', mode: 'auto', headers: {},
-        xPaddingBytes: '100-1000', scMaxEachPostBytes: '1000000',
+        xPaddingBytes: '100-1000',
       };
       break;
     default:

frontend/src/lib/xray/stream-wire-normalize.ts

@@ -125,6 +125,8 @@ export function normalizeXhttpForWire(
   }
 
   dropEmptyStrings(out, PLACEMENT_STRING_FIELDS);
+  // Empty tuning fields mean "use xray-core's default" — never emit them.
+  dropEmptyStrings(out, ['scMaxEachPostBytes', 'scMinPostsIntervalMs', 'scStreamUpServerSecs']);
 
   if (!hasMeaningfulHeaders(out.headers)) {
     delete out.headers;