chore(core): add well-known api doc descriptions (#5018)

packages/core/src/routes/well-known.openapi.json

@@ -0,0 +1,50 @@
+{
+  "tags": [
+    {
+      "name": "Well-Known",
+      "description": "Well-Known routes provide information and resources that can be discovered by clients without the need for authentication."
+    }
+  ],
+  "paths": {
+    "/api/.well-known/endpoints/{tenantId}": {
+      "get": {
+        "summary": "Get tenant endpoint",
+        "description": "Get the endpoint for the specified tenant.",
+        "responses": {
+          "200": {
+            "description": "The tenant endpoint."
+          }
+        }
+      }
+    },
+    "/api/.well-known/sign-in-exp": {
+      "get": {
+        "summary": "Get full sign-in experience",
+        "description": "Get the full sign-in experience configuration.",
+        "responses": {
+          "200": {
+            "description": "The full sign-in experience configuration."
+          }
+        }
+      }
+    },
+    "/api/.well-known/phrases": {
+      "get": {
+        "summary": "Get localized phrases",
+        "description": "Get localized phrases based on the specified language.",
+        "parameters": [
+          {
+            "name": "lng",
+            "in": "query",
+            "description": "The language tag for localization."
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Localized phrases for the specified language."
+          }
+        }
+      }
+    }
+  }
+}