feat(reality): derive a stable per-client spiderX for shared links

The inbound's spiderX now acts as a per-client seed: exports emit
sha256(seed|subKey) truncated to a 15-hex "/path", so a client's spx no
longer changes on every subscription fetch (#5718) while different
clients stop sharing one fingerprintable value. The form gains a
regenerate button that rotates every client's path at once.

The frontend link builders derive through the same function
(lib/xray/spider-x.ts, @noble/hashes) keyed on subId-then-email like
the Go subKey, so panel QR/copy links and subscription output agree —
cross-language vector tests lock both sides byte-for-byte. streamData
now tolerates malformed stored stream settings (unparseable JSON, null
tls/reality settings) instead of panicking the subscription request.

frontend/src/pages/inbounds/form/InboundFormModal.tsx

@@ -248,6 +248,7 @@ export default function InboundFormModal({
     scanRealityCandidates,
     applyRealityScanResult,
     randomizeShortIds,
+    randomizeSpiderX,
     getNewEchCert,
     clearEchCert,
     pinFromCert,
@@ -896,6 +897,7 @@ export default function InboundFormModal({
           scanRealityCandidates={scanRealityCandidates}
           applyRealityScanResult={applyRealityScanResult}
           randomizeShortIds={randomizeShortIds}
+          randomizeSpiderX={randomizeSpiderX}
           genRealityKeypair={genRealityKeypair}
           clearRealityKeypair={clearRealityKeypair}
           genMldsa65={genMldsa65}