feat(agent): /clear now clears seahorse DB in addition to JSONL

- Add Clear(ctx, sessionKey) to ContextManager interface
- Implement Clear for legacy (JSONL) and seahorse (DB + JSONL)
- Add Engine.ClearSession + Store.ClearConversation
- Fix FTS5 DELETE trigger syntax in schema (was using wrong
  external-content FTS5 syntax; now uses standard DELETE FROM)
- Fix ClearSession to skip sessions never ingested (was creating
  blank conversations record via GetOrCreateConversation)
- Simplify summary_parents DELETE into single OR statement
- Add TestStoreClearConversation unit test

pkg/agent/context_legacy.go

@@ -61,6 +61,16 @@ func (m *legacyContextManager) Ingest(_ context.Context, _ *IngestRequest) error
 	return nil
 }
 
+func (m *legacyContextManager) Clear(_ context.Context, sessionKey string) error {
+	agent := m.al.registry.GetDefaultAgent()
+	if agent == nil || agent.Sessions == nil {
+		return fmt.Errorf("sessions not initialized")
+	}
+	agent.Sessions.SetHistory(sessionKey, []providers.Message{})
+	agent.Sessions.SetSummary(sessionKey, "")
+	return agent.Sessions.Save(sessionKey)
+}
+
 // maybeSummarize triggers summarization if the session history exceeds thresholds.
 // It runs asynchronously in a goroutine.
 func (m *legacyContextManager) maybeSummarize(sessionKey string) {

pkg/agent/context_manager.go

@@ -24,6 +24,10 @@ type ContextManager interface {
 	// Ingest records a message into the ContextManager's own storage.
 	// Called after each message is persisted to session JSONL.
 	Ingest(ctx context.Context, req *IngestRequest) error
+
+	// Clear removes all stored context for a session (messages, summaries, etc.).
+	// Called when the user issues /clear or /reset.
+	Clear(ctx context.Context, sessionKey string) error
 }
 
 // AssembleRequest is the input to Assemble.

pkg/agent/context_manager_test.go

@@ -690,6 +690,7 @@ func (m *noopContextManager) Assemble(_ context.Context, req *AssembleRequest) (
 }
 func (m *noopContextManager) Compact(_ context.Context, _ *CompactRequest) error { return nil }
 func (m *noopContextManager) Ingest(_ context.Context, _ *IngestRequest) error   { return nil }
+func (m *noopContextManager) Clear(_ context.Context, _ string) error            { return nil }
 
 // trackingContextManager tracks call counts for each method.
 type trackingContextManager struct {
@@ -726,6 +727,8 @@ func (m *trackingContextManager) Ingest(_ context.Context, req *IngestRequest) e
 	return nil
 }
 
+func (m *trackingContextManager) Clear(_ context.Context, _ string) error { return nil }
+
 // resetCMRegistry clears the global factory registry and returns a cleanup
 // function that restores the original state after the test.
 func resetCMRegistry() func() {

pkg/agent/context_seahorse.go

@@ -154,6 +154,19 @@ func (m *seahorseContextManager) Ingest(ctx context.Context, req *IngestRequest)
 	return err
 }
 
+// Clear removes all stored context for a session (seahorse DB + JSONL).
+func (m *seahorseContextManager) Clear(ctx context.Context, sessionKey string) error {
+	if err := m.engine.ClearSession(ctx, sessionKey); err != nil {
+		return err
+	}
+	if m.sessions != nil {
+		m.sessions.SetHistory(sessionKey, []providers.Message{})
+		m.sessions.SetSummary(sessionKey, "")
+		return m.sessions.Save(sessionKey)
+	}
+	return nil
+}
+
 // bootstrapSession reconciles JSONL session history into seahorse SQLite.
 func (m *seahorseContextManager) bootstrapSession(ctx context.Context, sessionKey string) {
 	if m.sessions == nil {

pkg/agent/loop.go

@@ -3368,7 +3368,7 @@ func (al *AgentLoop) handleCommand(
 		return "", false
 	}
 
-	rt := al.buildCommandsRuntime(agent, opts)
+	rt := al.buildCommandsRuntime(ctx, agent, opts)
 	executor := commands.NewExecutor(al.cmdRegistry, rt)
 
 	var commandReply string
@@ -3488,7 +3488,11 @@ func (al *AgentLoop) applyExplicitSkillCommand(
 	return true, false, ""
 }
 
-func (al *AgentLoop) buildCommandsRuntime(agent *AgentInstance, opts *processOptions) *commands.Runtime {
+func (al *AgentLoop) buildCommandsRuntime(
+	ctx context.Context,
+	agent *AgentInstance,
+	opts *processOptions,
+) *commands.Runtime {
 	registry := al.GetRegistry()
 	cfg := al.GetConfig()
 	rt := &commands.Runtime{
@@ -3570,14 +3574,7 @@ func (al *AgentLoop) buildCommandsRuntime(agent *AgentInstance, opts *processOpt
 			if opts == nil {
 				return fmt.Errorf("process options not available")
 			}
-			if agent.Sessions == nil {
-				return fmt.Errorf("sessions not initialized for agent")
-			}
-
-			agent.Sessions.SetHistory(opts.SessionKey, make([]providers.Message, 0))
-			agent.Sessions.SetSummary(opts.SessionKey, "")
-			agent.Sessions.Save(opts.SessionKey)
-			return nil
+			return al.contextManager.Clear(ctx, opts.SessionKey)
 		}
 	}
 	return rt

pkg/seahorse/schema.go

@@ -123,10 +123,10 @@ func runSchema(db *sql.DB) error {
 			INSERT INTO summaries_fts (summary_id, content) VALUES (new.summary_id, new.content);
 		END`,
 		`CREATE TRIGGER IF NOT EXISTS summaries_ad AFTER DELETE ON summaries BEGIN
-			INSERT INTO summaries_fts (summaries_fts, summary_id, content) VALUES ('delete', old.summary_id, old.content);
+			DELETE FROM summaries_fts WHERE summary_id = old.summary_id;
 		END`,
 		`CREATE TRIGGER IF NOT EXISTS summaries_au AFTER UPDATE ON summaries BEGIN
-			INSERT INTO summaries_fts (summaries_fts, summary_id, content) VALUES ('delete', old.summary_id, old.content);
+			DELETE FROM summaries_fts WHERE summary_id = old.summary_id;
 			INSERT INTO summaries_fts (summary_id, content) VALUES (new.summary_id, new.content);
 		END`,
 

pkg/seahorse/short_engine.go

@@ -377,6 +377,19 @@ func (e *Engine) IngestMessages(ctx context.Context, sessionKey string, messages
 	return e.Ingest(ctx, sessionKey, messages)
 }
 
+// ClearSession removes all stored data for a session (messages, summaries, context).
+// If the session has no prior seahorse record, it is a no-op.
+func (e *Engine) ClearSession(ctx context.Context, sessionKey string) error {
+	conv, err := e.store.GetConversationBySessionKey(ctx, sessionKey)
+	if err != nil {
+		return err
+	}
+	if conv == nil {
+		return nil // session never ingested, nothing to clear
+	}
+	return e.store.ClearConversation(ctx, conv.ConversationID)
+}
+
 // Bootstrap reconciles a session's messages with the database.
 // Called once at startup for each known session.
 // Bootstrap reconciles JSONL history with SQLite by ingesting only the delta.

pkg/seahorse/store.go

@@ -728,6 +728,57 @@ func (s *Store) DeleteMessagesAfterID(ctx context.Context, convID int64, afterID
 	return tx.Commit()
 }
 
+// ClearConversation removes all data for a conversation from all tables.
+// Deletes context_items, summary_messages, summary_parents (via subquery), summaries,
+// message_parts, and messages. FTS entries are handled automatically by triggers.
+// Uses a transaction for atomicity.
+func (s *Store) ClearConversation(ctx context.Context, convID int64) error {
+	tx, err := s.db.BeginTx(ctx, nil)
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback()
+
+	// Delete in child→parent order. FTS tables (messages_fts, summaries_fts) are
+	// kept in sync by DELETE triggers, so we just delete from the parent tables.
+
+	if _, err := tx.ExecContext(ctx,
+		"DELETE FROM context_items WHERE conversation_id = ?", convID); err != nil {
+		return fmt.Errorf("context_items: %w", err)
+	}
+	if _, err := tx.ExecContext(ctx,
+		`DELETE FROM summary_messages WHERE summary_id IN (
+			SELECT summary_id FROM summaries WHERE conversation_id = ?
+		)`, convID); err != nil {
+		return fmt.Errorf("summary_messages: %w", err)
+	}
+	// Note: summary_parents has no convID column; delete via subquery on summaries
+	if _, err := tx.ExecContext(ctx,
+		`DELETE FROM summary_parents WHERE summary_id IN (
+			SELECT summary_id FROM summaries WHERE conversation_id = ?
+		) OR parent_summary_id IN (
+			SELECT summary_id FROM summaries WHERE conversation_id = ?
+		)`, convID, convID); err != nil {
+		return fmt.Errorf("summary_parents: %w", err)
+	}
+	if _, err := tx.ExecContext(ctx,
+		"DELETE FROM summaries WHERE conversation_id = ?", convID); err != nil {
+		return fmt.Errorf("summaries: %w", err)
+	}
+	if _, err := tx.ExecContext(ctx,
+		`DELETE FROM message_parts WHERE message_id IN (
+			SELECT message_id FROM messages WHERE conversation_id = ?
+		)`, convID); err != nil {
+		return fmt.Errorf("message_parts: %w", err)
+	}
+	if _, err := tx.ExecContext(ctx,
+		"DELETE FROM messages WHERE conversation_id = ?", convID); err != nil {
+		return fmt.Errorf("messages: %w", err)
+	}
+
+	return tx.Commit()
+}
+
 // AppendContextMessage appends a single message to context_items at next ordinal.
 func (s *Store) AppendContextMessage(ctx context.Context, convID int64, messageID int64) error {
 	return s.appendContextItems(ctx, convID, []ContextItem{

pkg/seahorse/store_test.go

@@ -79,7 +79,95 @@ func TestStoreGetConversationBySessionKey(t *testing.T) {
 	}
 }
 
-// --- Message Operations ---
+// --- Conversation Clear ---
+
+func TestStoreClearConversation(t *testing.T) {
+	s := openTestStore(t)
+	ctx := context.Background()
+
+	conv, err := s.GetOrCreateConversation(ctx, "agent:clear-test")
+	if err != nil {
+		t.Fatalf("create conversation: %v", err)
+	}
+
+	// Add messages
+	msg1, err := s.AddMessage(ctx, conv.ConversationID, "user", "hello", 5)
+	if err != nil {
+		t.Fatalf("add message 1: %v", err)
+	}
+	msg2, err := s.AddMessage(ctx, conv.ConversationID, "assistant", "hi", 5)
+	if err != nil {
+		t.Fatalf("add message 2: %v", err)
+	}
+
+	// Add a summary
+	_, err = s.CreateSummary(ctx, CreateSummaryInput{
+		ConversationID: conv.ConversationID,
+		Content:        "test summary",
+		TokenCount:     10,
+		Kind:           SummaryKindLeaf,
+	})
+	if err != nil {
+		t.Fatalf("create summary: %v", err)
+	}
+
+	// Verify data exists
+	msgs, err := s.GetMessages(ctx, conv.ConversationID, 0, 0)
+	if err != nil {
+		t.Fatalf("get messages before clear: %v", err)
+	}
+	if len(msgs) != 2 {
+		t.Fatalf("expected 2 messages before clear, got %d", len(msgs))
+	}
+
+	sums, err := s.GetSummariesByConversation(ctx, conv.ConversationID)
+	if err != nil {
+		t.Fatalf("get summaries before clear: %v", err)
+	}
+	if len(sums) != 1 {
+		t.Fatalf("expected 1 summary before clear, got %d", len(sums))
+	}
+
+	// Clear
+	if err = s.ClearConversation(ctx, conv.ConversationID); err != nil {
+		t.Fatalf("clear conversation: %v", err)
+	}
+
+	// Verify all data is gone
+	msgs, err = s.GetMessages(ctx, conv.ConversationID, 0, 0)
+	if err != nil {
+		t.Fatalf("get messages after clear: %v", err)
+	}
+	if len(msgs) != 0 {
+		t.Fatalf("expected 0 messages after clear, got %d", len(msgs))
+	}
+
+	sums, err = s.GetSummariesByConversation(ctx, conv.ConversationID)
+	if err != nil {
+		t.Fatalf("get summaries after clear: %v", err)
+	}
+	if len(sums) != 0 {
+		t.Fatalf("expected 0 summaries after clear, got %d", len(sums))
+	}
+
+	items, err := s.GetContextItems(ctx, conv.ConversationID)
+	if err != nil {
+		t.Fatalf("get context items after clear: %v", err)
+	}
+	if len(items) != 0 {
+		t.Fatalf("expected 0 context items after clear, got %d", len(items))
+	}
+
+	var count int
+	if err := s.db.QueryRowContext(ctx,
+		"SELECT COUNT(*) FROM message_parts WHERE message_id = ? OR message_id = ?",
+		msg1.ID, msg2.ID).Scan(&count); err != nil {
+		t.Fatalf("count message parts: %v", err)
+	}
+	if count != 0 {
+		t.Fatalf("expected 0 message parts after clear, got %d", count)
+	}
+}
 
 func TestStoreAddAndGetMessages(t *testing.T) {
 	s := openTestStore(t)