[Feature] Put subject first in LLM embedding input

Subject is highly valuable for spam detection and placing it first
ensures it's always included even if text content gets truncated
by model token limits.

diff --git a/lualib/plugins/neural/providers/llm.lua b/lualib/plugins/neural/providers/llm.lua
index 9709c231edebe9ccc76978aa9c78adf2f67b5ad8..95e5657a520fd9c3250807340a96f348faf612a6 100644 (file)
--- a/lualib/plugins/neural/providers/llm.lua
+++ b/lualib/plugins/neural/providers/llm.lua
@@ -151,10 +151,13 @@ neural_common.register_provider('llm', {
       return
     end
 
-    -- Build request input string (text then optional subject), keeping rspamd_text intact
-    local input_string = input_tbl.text or ''
+    -- Build request input string: subject first (more valuable for spam detection),
+    -- then text content. Subject-first ensures it's always included even if text is truncated.
+    local input_string
     if input_tbl.subject and input_tbl.subject ~= '' then
-      input_string = input_string .. "\nSubject: " .. input_tbl.subject
+      input_string = "Subject: " .. input_tbl.subject .. "\n" .. (input_tbl.text or '')
+    else
+      input_string = input_tbl.text or ''
     end
 
     local input_key = normalize_cache_key_input(input_string)