feat(suggestions): add tags around json (#1441)

lua/avante/suggestion.lua

@@ -110,6 +110,7 @@ L5:     pass
     {
       role = "assistant",
       content = [[
+<suggestions>
 [
   [
     {
@@ -136,6 +137,7 @@ L5:     pass
     },
   ]
 ]
+</suggestions>
           ]],
     },
   }
@@ -165,6 +167,7 @@ L5:     pass
         if cursor_row ~= doc.position.row or cursor_col ~= doc.position.col then return end
         -- Clean up markdown code blocks
         full_response = Utils.trim_think_content(full_response)
+        full_response = full_response:gsub("<suggestions>\n(.-)\n</suggestions>", "%1")
         full_response = full_response:gsub("^```%w*\n(.-)\n```$", "%1")
         full_response = full_response:gsub("(.-)\n```\n?$", "%1")
         -- Remove everything before the first '[' to ensure we get just the JSON array