feat(nodes): add distinct purple indicator when panel is online but Xray core failed (#5040)

* feat(nodes): add distinct purple indicator when panel is online but Xray core failed

Currently nodes only show binary online/offline based on panel API reachability.

This adds a third state:
- Green: panel reachable + Xray healthy
- Purple pulsing dot + "Online (Xray Error)": panel API works (management actions still available) but the node Xray process is in error or stopped. Tooltip shows the remote xrayError.
- Red: unreachable (unchanged)

Backend now captures xray.state + xray.errorMsg from /panel/api/server/status heartbeats and probes.
New fields on Node + NodeSummary, forwarded for transitive nodes.
Frontend Zod + NodeList rendering + dedicated .xray-error-dot CSS (color #722ED1) + i18n key.

Color chosen purple per feedback after initial implementation.

Refs: worktree xray-failed-in-nodes

* fix: remove invalid JSON comment causing CI failures

* chore: regenerate OpenAPI schemas and types for xray error indicators

* chore: regenerate examples and schemas for xray error indicators

* chore: regenerate missing openapi.json examples

* fix

---------

Co-authored-by: Rqzbeh <rqzbeh@users.noreply.github.com>
Co-authored-by: Sanaei <ho3ein.sanaei@gmail.com>

frontend/src/generated/examples.ts

@@ -364,6 +364,8 @@ export const EXAMPLES: Record<string, unknown> = {
     "transitive": false,
     "updatedAt": 1700000000,
     "uptimeSecs": 86400,
+    "xrayError": "",
+    "xrayState": "",
     "xrayVersion": "25.10.31"
   },
   "OutboundTraffics": {
@@ -381,6 +383,8 @@ export const EXAMPLES: Record<string, unknown> = {
     "panelVersion": "v3.x.x",
     "status": "online",
     "uptimeSecs": 86400,
+    "xrayError": "",
+    "xrayState": "",
     "xrayVersion": "25.10.31"
   },
   "Setting": {