fix: enhance WebSocket stability, resolve XHTTP configurations and fix UI loading shifts (#3997)

* feat: implement real-time traffic monitoring and UI updates using a high-performance WebSocket hub and background job system

* feat: add bulk client management support and improve inbound data handling

* Fix bug

* **Fixes & Changes:**
1. **Fixed XPadding Placement Dropdown**:
   - Added the missing `cookie` and `query` options to `xPaddingPlacement` (`stream_xhttp.html`).
   - *Why:* Previously, users wanting `cookie` obfuscation were forced to use the `header` placement string. This caused Xray-core to blindly intercept the entire monolithic HTTP Cookie header, failing internal padding-length validations and causing the inbound to silently drop the connection.
2. **Fixed Uplink Data Placement Validation**:
   - Replaced the unsupported `query` option with `cookie` in `uplinkDataPlacement`.
   - *Why:* Xray-core's `transport_internet.go` explicitly forbids `query` as an uplink placement option. Selecting it from the UI previously sent a payload that would cause Xray-core to instantly throw an `unsupported uplink data placement: query` panic. Adding `cookie` perfectly aligns the UI with Xray-core restrictions.
### Related Issues
- Resolves #3992

* This commit fixes structural payload issues preventing XHTTP from functioning correctly and eliminates WebSocket log spam.
- **[Fix X-Padding UI]** Added missing `cookie` and `query` options to X-Padding Placement. Fixes the issue where using Cookie fallback triggers whole HTTP Cookie header interception and silent drop in Xray-core. (Resolves [#3992](https://github.com/MHSanaei/3x-ui/issues/3992))
- **[Fix Uplink Data Options]** Replaced the invalid `query` option with `cookie` in Uplink Data Placement dropdown to prevent Xray-core backend panic `unsupported uplink data placement: query`.
- **[Fix WebSockets Spam]** Boosted `maxMessageSize` boundary to 100MB and gracefully handled fallback fetch signals via `broadcastInvalidate` to avoid buffer dropping spam. (Resolves [#3984](https://github.com/MHSanaei/3x-ui/issues/3984))

* Fix

* gofmt

* fix(websocket): resolve channel race condition and graceful shutdown deadlock

* Fix: inbounds switch

* Change max quantity from 10000 to 500

* fix

web/html/index.html

@@ -6,7 +6,7 @@
   <a-sidebar></a-sidebar>
   <a-layout id="content-layout">
     <a-layout-content>
-      <a-spin :spinning="loadingStates.spinning" :delay="200" :tip="loadingTip">
+      <a-spin :spinning="loadingStates.spinning" :delay="200" :tip="loadingTip" size="large">
         <transition name="list" appear>
           <a-alert type="error" v-if="showAlert && loadingStates.fetched" class="mb-10"
             message='{{ i18n "secAlertTitle" }}' color="red" description='{{ i18n "secAlertSsl" }}' show-icon closable>
@@ -15,9 +15,7 @@
         <transition name="list" appear>
           <template>
             <a-row v-if="!loadingStates.fetched">
-              <a-card class="card-placeholder text-center">
-                <a-spin tip='{{ i18n "loading" }}'></a-spin>
-              </a-card>
+              <div :style="{ minHeight: 'calc(100vh - 120px)' }"></div>
             </a-row>
             <a-row :gutter="[isMobile ? 8 : 16, isMobile ? 0 : 12]" v-else>
               <a-col>