Add semantic search for chat history

- Add chat_history table with embeddings in memory.db
- Add saveChatHistoryEntry for live message ingestion
- Add searchChatHistorySemantic for vector similarity search
- Update search_chat_history tool to use semantic search
- Add backfill command: run.sh Omni/Agent/Memory.hs backfill
- Add stats command: run.sh Omni/Agent/Memory.hs stats
- Change default memory.db path to ~/memory.db
- Wire Telegram message handling to save to chat_history async

1 files changed, 39 insertions, 26 deletions

diff --git a/Omni/Agent/Tools/AvaLogs.hs b/Omni/Agent/Tools/AvaLogs.hs
index 84c9db8..4c8ce11 100644
--- a/Omni/Agent/Tools/AvaLogs.hs
+++ b/Omni/Agent/Tools/AvaLogs.hs
@@ -24,6 +24,7 @@ import qualified Data.Text as Text
 import qualified Data.Time as Time
 import qualified Omni.Agent.AuditLog as AuditLog
 import qualified Omni.Agent.Engine as Engine
+import qualified Omni.Agent.Memory as Memory
 
 main :: IO ()
 main = putText "Omni.Agent.Tools.AvaLogs - no standalone execution"
@@ -114,9 +115,9 @@ searchChatHistoryTool =
   Engine.Tool
     { Engine.toolName = "search_chat_history",
       Engine.toolDescription =
-        "Search your conversation history for specific content. "
+        "Search your conversation history using semantic similarity. "
           <> "Use this to find what was said in past conversations, recall context, "
-          <> "or find when something was discussed. Searches message content.",
+          <> "or find when something was discussed. Finds semantically related messages.",
       Engine.toolJsonSchema =
         Aeson.object
           [ "type" .= ("object" :: Text),
@@ -125,12 +126,7 @@ searchChatHistoryTool =
                 [ "query"
                     .= Aeson.object
                       [ "type" .= ("string" :: Text),
-                        "description" .= ("Text to search for in chat history" :: Text)
-                      ],
-                  "days_back"
-                    .= Aeson.object
-                      [ "type" .= ("integer" :: Text),
-                        "description" .= ("How many days back to search (default: 7)" :: Text)
+                        "description" .= ("What to search for (semantic search)" :: Text)
                       ],
                   "max_results"
                     .= Aeson.object
@@ -151,12 +147,6 @@ executeSearchHistory v = do
           _ -> ""
         _ -> ""
 
-  let daysBack = case v of
-        Aeson.Object obj -> case KeyMap.lookup "days_back" obj of
-          Just (Aeson.Number n) -> round n
-          _ -> 7
-        _ -> 7
-
   let maxResults = case v of
         Aeson.Object obj -> case KeyMap.lookup "max_results" obj of
           Just (Aeson.Number n) -> round n
@@ -166,18 +156,41 @@ executeSearchHistory v = do
   if Text.null query
     then pure <| Aeson.object ["error" .= ("query is required" :: Text)]
     else do
-      today <- Time.utctDay </ Time.getCurrentTime
-      let days = [Time.addDays (negate i) today | i <- [0 .. daysBack - 1]]
-      allEntries <- concat </ traverse AuditLog.readAvaLogs days
-      let matches = filter (matchesQuery query) allEntries
-          limited = take maxResults matches
-      pure
-        <| Aeson.object
-          [ "query" .= query,
-            "days_searched" .= daysBack,
-            "total_matches" .= length matches,
-            "results" .= map formatSearchResult limited
-          ]
+      (_total, indexed) <- Memory.getChatHistoryStats
+      if indexed > 0
+        then do
+          results <- Memory.searchChatHistorySemantic query maxResults
+          pure
+            <| Aeson.object
+              [ "query" .= query,
+                "search_type" .= ("semantic" :: Text),
+                "indexed_messages" .= indexed,
+                "results" .= map formatSemanticResult results
+              ]
+        else do
+          today <- Time.utctDay </ Time.getCurrentTime
+          let days = [Time.addDays (negate i) today | i <- [0 .. 6]]
+          allEntries <- concat </ traverse AuditLog.readAvaLogs days
+          let matches = filter (matchesQuery query) allEntries
+              limited = take maxResults matches
+          pure
+            <| Aeson.object
+              [ "query" .= query,
+                "search_type" .= ("keyword_fallback" :: Text),
+                "note" .= ("no indexed history - run backfill" :: Text),
+                "total_matches" .= length matches,
+                "results" .= map formatSearchResult limited
+              ]
+
+formatSemanticResult :: (Memory.ChatHistoryEntry, Float) -> Aeson.Value
+formatSemanticResult (entry, score) =
+  Aeson.object
+    [ "timestamp" .= Time.formatTime Time.defaultTimeLocale "%Y-%m-%d %H:%M:%S" (Memory.cheCreatedAt entry),
+      "role" .= Memory.cheRole entry,
+      "sender" .= Memory.cheSenderName entry,
+      "similarity" .= score,
+      "content" .= Text.take 500 (Memory.cheContent entry)
+    ]
 
 matchesQuery :: Text -> AuditLog.AuditLogEntry -> Bool
 matchesQuery query entry =