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/public/openapi.json

@@ -1656,6 +1656,13 @@
             "example": 86400,
             "type": "integer"
           },
+          "xrayError": {
+            "type": "string"
+          },
+          "xrayState": {
+            "description": "XrayState and XrayError are captured from the remote node's /panel/api/server/status\nduring heartbeats. They let the central panel distinguish \"panel API reachable\"\n(status=online) from \"Xray core itself has failed on the node\" for monitoring.",
+            "type": "string"
+          },
           "xrayVersion": {
             "example": "25.10.31",
             "type": "string"
@@ -1691,6 +1698,8 @@
           "tlsVerifyMode",
           "updatedAt",
           "uptimeSecs",
+          "xrayError",
+          "xrayState",
           "xrayVersion"
         ],
         "type": "object"
@@ -1752,6 +1761,13 @@
             "example": 86400,
             "type": "integer"
           },
+          "xrayError": {
+            "type": "string"
+          },
+          "xrayState": {
+            "description": "XrayState/XrayError are populated on successful probes even when the node's\nXray core is not healthy. The UI uses them for a distinct \"panel ok, xray failed\" indicator.",
+            "type": "string"
+          },
           "xrayVersion": {
             "example": "25.10.31",
             "type": "string"
@@ -1765,6 +1781,8 @@
           "panelVersion",
           "status",
           "uptimeSecs",
+          "xrayError",
+          "xrayState",
           "xrayVersion"
         ],
         "type": "object"
@@ -5894,6 +5912,8 @@
                       "transitive": false,
                       "updatedAt": 1700000000,
                       "uptimeSecs": 86400,
+                      "xrayError": "",
+                      "xrayState": "",
                       "xrayVersion": "25.10.31"
                     }
                   ]
@@ -6254,6 +6274,8 @@
                     "panelVersion": "v3.x.x",
                     "status": "online",
                     "uptimeSecs": 86400,
+                    "xrayError": "",
+                    "xrayState": "",
                     "xrayVersion": "25.10.31"
                   }
                 }