feat(xhttp): support sessionID* rename + sessionIDTable/Length (xray v26.6.22) (#5506)

* feat(xhttp): support sessionID* rename + sessionIDTable/Length (xray v26.6.22)

xray-core v26.6.22 (PR #6258) renamed the XHTTP session config keys
sessionPlacement/sessionKey to sessionIDPlacement/sessionIDKey (no fallback
kept in core) and added sessionIDTable (predefined charset name or literal
ASCII) and sessionIDLength (range, e.g. 16-32, lower bound > 0).

Panel changes:
- Schema (xhttp.ts): rename the two keys, add sessionIDTable/sessionIDLength,
  and a z.preprocess that lifts legacy keys off stored configs so an upgraded
  panel never silently drops a saved session setting.
- Wire normalize + share-link build/parse: rename keys, emit the two new
  fields, and accept legacy sessionPlacement/sessionKey from old share links.
- Inbound + outbound XHTTP forms: rename field paths, add a sessionIDTable
  autocomplete (9 predefined tables + free ASCII) and a sessionIDLength range
  input shown only when a table is set, with light client validation (ASCII
  table, length min > 0; xray enforces the room-size minimum server-side).
- Subscription (service.go) and Clash (clash_service.go) builders: emit the
  renamed + new keys, with a legacy fallback for not-yet-resaved inbounds.
- Locales: add sessionIDTable/sessionIDLength labels + hints in all 13 files.

Two sibling v26.6.22 XHTTP commits need no panel change and are covered by the
core bump alone: #6332 (XHTTP/3 closes QUIC/UDP) and #6320 (udpHop honors the
existing dialerProxy).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* test(xhttp): add Session ID Table to inbound form-blocks snapshot

The new sessionIDTable input renders by default in the inbound XHTTP form, so
its label joins the field-structure snapshot. sessionIDLength stays conditional
(only shown when a table is set), so it does not appear here.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* fix(xhttp): migrate legacy session keys in the running xray config

The Zod preprocess plus the subscription/Clash fallbacks only covered the
panel UI and share-link output. The config handed to the running xray-core
process is built from the raw stored streamSettings in GetXrayConfig, which
did not rewrite the renamed XHTTP session keys — so a pre-upgrade inbound (or
template outbound) stored with a non-default sessionPlacement was emitted
unchanged and dropped by xray-core v26.6.22, until the admin re-saved it.

Lift sessionPlacement/sessionKey onto sessionIDPlacement/sessionIDKey at
config-generation time, in the existing inbound stream-rewrite block (next to
the tls/reality/externalProxy handling) and across template outbounds. The
lift is idempotent and leaves unchanged configs byte-identical so the
hot-reload diff never sees a spurious change.

Also tighten validateSessionIDLength to reject an inverted range (e.g. 32-16)
in addition to the existing lower-bound > 0 check.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* fix(xray): avoid summed-capacity allocation in mergeSubscriptionOutbounds

CodeQL go/allocation-size-overflow flagged the pre-sized make() whose
capacity was a sum of three slice lengths. Grow the slice via append on
a nil slice instead; same result, no overflow-prone capacity expression.

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

@@ -24,10 +24,18 @@ type Raw = Record<string, unknown>;
 // match the schema's authoring order so diffs read naturally.
 const XHTTP_STRING_KEYS = [
   'xPaddingBytes', 'xPaddingKey', 'xPaddingHeader', 'xPaddingPlacement',
-  'xPaddingMethod', 'sessionPlacement', 'sessionKey', 'seqPlacement',
-  'seqKey', 'uplinkDataPlacement', 'uplinkDataKey', 'scMaxEachPostBytes',
-  'scMinPostsIntervalMs', 'scStreamUpServerSecs', 'uplinkHTTPMethod',
+  'xPaddingMethod', 'sessionIDPlacement', 'sessionIDKey', 'sessionIDTable',
+  'sessionIDLength', 'seqPlacement', 'seqKey', 'uplinkDataPlacement',
+  'uplinkDataKey', 'scMaxEachPostBytes', 'scMinPostsIntervalMs',
+  'scStreamUpServerSecs', 'uplinkHTTPMethod',
 ] as const;
+// Legacy share links (pre xray-core #6258) carry sessionPlacement/sessionKey.
+// Map them onto the renamed keys so old links still import. Mirrors the
+// schema-level migrateLegacyXhttp.
+const XHTTP_LEGACY_ALIASES: Record<string, string> = {
+  sessionPlacement: 'sessionIDPlacement',
+  sessionKey: 'sessionIDKey',
+};
 const XHTTP_NUMBER_KEYS = [
   'scMaxBufferedPosts', 'serverMaxHeaderBytes', 'uplinkChunkSize',
 ] as const;
@@ -81,12 +89,24 @@ function applyXhttpStringFromParams(xhttp: Raw, params: URLSearchParams): void {
     const v = params.get(k);
     if (v !== null && v !== '') xhttp[k] = asBool(v);
   }
+  // Fill renamed keys from legacy params only when the new key is absent.
+  for (const [legacy, renamed] of Object.entries(XHTTP_LEGACY_ALIASES)) {
+    if (xhttp[renamed] === undefined) {
+      const v = params.get(legacy);
+      if (v !== null && v !== '') xhttp[renamed] = v;
+    }
+  }
 }
 
 function applyXhttpStringFromJson(xhttp: Raw, json: Record<string, unknown>): void {
   for (const k of XHTTP_STRING_KEYS) {
     if (typeof json[k] === 'string') xhttp[k] = json[k];
   }
+  for (const [legacy, renamed] of Object.entries(XHTTP_LEGACY_ALIASES)) {
+    if (xhttp[renamed] === undefined && typeof json[legacy] === 'string') {
+      xhttp[renamed] = json[legacy];
+    }
+  }
   for (const k of XHTTP_NUMBER_KEYS) {
     if (typeof json[k] === 'number') xhttp[k] = json[k];
   }