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/pages/xray/outbounds/outbound-form-helpers.ts

@@ -45,7 +45,7 @@ export function newStreamSlice(network: string): Record<string, unknown> {
         network: 'xhttp',
         xhttpSettings: {
           path: '/', host: '', mode: '', headers: [],
-          xPaddingBytes: '100-1000', scMaxEachPostBytes: '1000000',
+          xPaddingBytes: '100-1000',
         },
       };
     case 'hysteria':