Telegram: improve webhook config guidance and startup fallback

src/config/zod-schema.providers-core.ts

@@ -165,11 +165,37 @@ export const TelegramAccountSchemaBase = z
       .strict()
       .optional(),
     proxy: z.string().optional(),
-    webhookUrl: z.string().optional(),
-    webhookSecret: z.string().optional().register(sensitive),
-    webhookPath: z.string().optional(),
-    webhookHost: z.string().optional(),
-    webhookPort: z.number().int().positive().optional(),
+    webhookUrl: z
+      .string()
+      .optional()
+      .describe(
+        "Public HTTPS webhook URL registered with Telegram for inbound updates. This must be internet-reachable and requires channels.telegram.webhookSecret.",
+      ),
+    webhookSecret: z
+      .string()
+      .optional()
+      .describe(
+        "Secret token sent to Telegram during webhook registration and verified on inbound webhook requests. Telegram returns this value for verification; this is not the gateway auth token and not the bot token.",
+      )
+      .register(sensitive),
+    webhookPath: z
+      .string()
+      .optional()
+      .describe(
+        "Local webhook route path served by the gateway listener. Defaults to /telegram-webhook.",
+      ),
+    webhookHost: z
+      .string()
+      .optional()
+      .describe(
+        "Local bind host for the webhook listener. Defaults to 127.0.0.1; keep loopback unless you intentionally expose direct ingress.",
+      ),
+    webhookPort: z
+      .number()
+      .int()
+      .positive()
+      .optional()
+      .describe("Local bind port for the webhook listener. Defaults to 8787."),
     actions: z
       .object({
         reactions: z.boolean().optional(),