Add actor column to agent_events table

- Add 'actor' column to agent_events table (human/junior/system)
- Add System to CommentAuthor type (reused for actor) - Add SQL
FromField/ToField instances for CommentAuthor - Update insertAgentEvent
to accept actor parameter - Update all SELECT queries to include
actor column - Update Worker.hs to pass actor for all event types -
Guardrail events logged with System actor

Migration: ALTER TABLE adds column with default 'junior' for existing
rows.

Task-Id: t-213.1

1 files changed, 36 insertions, 24 deletions

diff --git a/Omni/Task/Core.hs b/Omni/Task/Core.hs
index 1212a56..41fcae4 100644
--- a/Omni/Task/Core.hs
+++ b/Omni/Task/Core.hs
@@ -140,8 +140,8 @@ data Fact = Fact
   }
   deriving (Show, Eq, Generic)
 
--- Comment author
-data CommentAuthor = Human | Junior
+-- Comment/event author (also used as Actor for timeline events)
+data CommentAuthor = Human | Junior | System
   deriving (Show, Eq, Read, Generic)
 
 -- Comment for task notes/context
@@ -266,16 +266,6 @@ instance SQL.FromField ActivityStage where
 instance SQL.ToField ActivityStage where
   toField x = SQL.toField (show x :: String)
 
-instance SQL.FromField CommentAuthor where
-  fromField f = do
-    t <- SQL.fromField f :: SQLOk.Ok String
-    case readMaybe t of
-      Just x -> pure x
-      Nothing -> SQL.returnError SQL.ConversionFailed f "Invalid CommentAuthor"
-
-instance SQL.ToField CommentAuthor where
-  toField x = SQL.toField (show x :: String)
-
 -- Store dependencies as JSON text
 instance SQL.FromField [Dependency] where
   fromField f = do
@@ -540,10 +530,16 @@ createAgentEventsTable conn = do
     \ session_id TEXT NOT NULL, \
     \ timestamp DATETIME DEFAULT CURRENT_TIMESTAMP, \
     \ event_type TEXT NOT NULL, \
-    \ content TEXT NOT NULL \
+    \ content TEXT NOT NULL, \
+    \ actor TEXT NOT NULL DEFAULT 'junior' \
     \)"
   SQL.execute_ conn "CREATE INDEX IF NOT EXISTS idx_agent_events_task ON agent_events(task_id)"
   SQL.execute_ conn "CREATE INDEX IF NOT EXISTS idx_agent_events_session ON agent_events(session_id)"
+  -- Add actor column to existing tables (migration)
+  SQL.execute_ conn "ALTER TABLE agent_events ADD COLUMN actor TEXT NOT NULL DEFAULT 'junior'" `catch` ignoreAlterError
+  where
+    ignoreAlterError :: SQL.SQLError -> IO ()
+    ignoreAlterError _ = pure () -- Column already exists
 
 -- | Expected columns for task_activity table (name, type, nullable)
 taskActivityColumns :: [(Text, Text)]
@@ -1609,6 +1605,20 @@ deleteFact fid =
 -- Agent Events (for observability)
 -- ============================================================================
 
+instance SQL.FromField CommentAuthor where
+  fromField f = do
+    t <- SQL.fromField f :: SQLOk.Ok String
+    case t of
+      "human" -> pure Human
+      "junior" -> pure Junior
+      "system" -> pure System
+      _ -> SQL.returnError SQL.ConversionFailed f "Invalid CommentAuthor"
+
+instance SQL.ToField CommentAuthor where
+  toField Human = SQL.toField ("human" :: String)
+  toField Junior = SQL.toField ("junior" :: String)
+  toField System = SQL.toField ("system" :: String)
+
 -- | Stored agent event record
 data StoredEvent = StoredEvent
   { storedEventId :: Int,
@@ -1616,7 +1626,8 @@ data StoredEvent = StoredEvent
     storedEventSessionId :: Text,
     storedEventTimestamp :: UTCTime,
     storedEventType :: Text,
-    storedEventContent :: Text
+    storedEventContent :: Text,
+    storedEventActor :: CommentAuthor
   }
   deriving (Show, Eq, Generic)
 
@@ -1633,6 +1644,7 @@ instance SQL.FromRow StoredEvent where
       <*> SQL.field
       <*> SQL.field
       <*> SQL.field
+      <*> SQL.field
 
 -- | Generate a new session ID (timestamp-based for simplicity)
 generateSessionId :: IO Text
@@ -1640,14 +1652,14 @@ generateSessionId = do
   now <- getCurrentTime
   pure <| "s-" <> T.pack (show now)
 
--- | Insert an agent event
-insertAgentEvent :: Text -> Text -> Text -> Text -> IO ()
-insertAgentEvent taskId sessionId eventType content =
+-- | Insert an agent event with actor
+insertAgentEvent :: Text -> Text -> Text -> Text -> CommentAuthor -> IO ()
+insertAgentEvent taskId sessionId eventType content actor =
   withDb <| \conn ->
     SQL.execute
       conn
-      "INSERT INTO agent_events (task_id, session_id, event_type, content) VALUES (?, ?, ?, ?)"
-      (taskId, sessionId, eventType, content)
+      "INSERT INTO agent_events (task_id, session_id, event_type, content, actor) VALUES (?, ?, ?, ?, ?)"
+      (taskId, sessionId, eventType, content, actor)
 
 -- | Get all events for a task (most recent session)
 getEventsForTask :: Text -> IO [StoredEvent]
@@ -1663,7 +1675,7 @@ getEventsForSession sessionId =
   withDb <| \conn ->
     SQL.query
       conn
-      "SELECT id, task_id, session_id, timestamp, event_type, content \
+      "SELECT id, task_id, session_id, timestamp, event_type, content, actor \
       \FROM agent_events WHERE session_id = ? ORDER BY id ASC"
       (SQL.Only sessionId)
 
@@ -1699,14 +1711,14 @@ getEventsSince sessionId lastId =
   withDb <| \conn ->
     SQL.query
       conn
-      "SELECT id, task_id, session_id, timestamp, event_type, content \
+      "SELECT id, task_id, session_id, timestamp, event_type, content, actor \
       \FROM agent_events WHERE session_id = ? AND id > ? ORDER BY id ASC"
       (sessionId, lastId)
 
 -- | Insert a checkpoint event (for progress tracking)
 insertCheckpoint :: Text -> Text -> Text -> IO ()
-insertCheckpoint taskId sessionId =
-  insertAgentEvent taskId sessionId "Checkpoint"
+insertCheckpoint taskId sessionId content =
+  insertAgentEvent taskId sessionId "Checkpoint" content Junior
 
 -- | Get all checkpoints for a task (across all sessions)
 getCheckpointsForTask :: Text -> IO [StoredEvent]
@@ -1714,7 +1726,7 @@ getCheckpointsForTask taskId =
   withDb <| \conn ->
     SQL.query
       conn
-      "SELECT id, task_id, session_id, timestamp, event_type, content \
+      "SELECT id, task_id, session_id, timestamp, event_type, content, actor \
       \FROM agent_events WHERE task_id = ? AND event_type = 'Checkpoint' ORDER BY id ASC"
       (SQL.Only taskId)