feat(web): hide ephemeral media refs from persisted session history

web/backend/api/session.go

@@ -5,7 +5,6 @@ import (
 	"encoding/json"
 	"errors"
 	"net/http"
-	"net/url"
 	"os"
 	"path/filepath"
 	"sort"
@@ -407,10 +406,12 @@ func (h *Handler) findLegacyPicoSession(dir, sessionID string) (picoLegacySessio
 }
 
 func buildSessionListItem(sessionID string, sess sessionFile, toolFeedbackMaxArgsLength int) sessionListItem {
+	transcript := visibleSessionMessages(sess.Messages, toolFeedbackMaxArgsLength)
+
 	preview := ""
-	for _, msg := range sess.Messages {
+	for _, msg := range transcript {
 		if msg.Role == "user" {
-			preview = sessionMessagePreview(msg)
+			preview = sessionChatMessagePreview(msg)
 		}
 		if preview != "" {
 			break
@@ -423,13 +424,11 @@ func buildSessionListItem(sessionID string, sess sessionFile, toolFeedbackMaxArg
 	}
 	title := preview
 
-	validMessageCount := len(visibleSessionMessages(sess.Messages, toolFeedbackMaxArgsLength))
-
 	return sessionListItem{
 		ID:           sessionID,
 		Title:        title,
 		Preview:      preview,
-		MessageCount: validMessageCount,
+		MessageCount: len(transcript),
 		Created:      sess.Created.Format(time.RFC3339),
 		Updated:      sess.Updated.Format(time.RFC3339),
 	}
@@ -450,11 +449,11 @@ func truncateRunes(s string, maxLen int) string {
 	return string(runes[:maxLen]) + "..."
 }
 
-func sessionMessageVisible(msg providers.Message) bool {
+func sessionChatMessageVisible(msg sessionChatMessage) bool {
 	return strings.TrimSpace(msg.Content) != "" || len(msg.Media) > 0 || len(msg.Attachments) > 0
 }
 
-func sessionMessagePreview(msg providers.Message) string {
+func sessionChatMessagePreview(msg sessionChatMessage) string {
 	if content := strings.TrimSpace(msg.Content); content != "" {
 		return content
 	}
@@ -484,13 +483,14 @@ func visibleSessionMessages(messages []providers.Message, toolFeedbackMaxArgsLen
 			continue
 
 		case "user":
-			if sessionMessageVisible(msg) {
+			chatMsg := sessionChatMessage{
-				transcript = append(transcript, sessionChatMessage{
 				Role:        "user",
 				Content:     msg.Content,
 				Media:       append([]string(nil), msg.Media...),
 				Attachments: attachments,
-				})
+			}
+			if sessionChatMessageVisible(chatMsg) {
+				transcript = append(transcript, chatMsg)
 			}
 
 		case "assistant":
@@ -513,10 +513,6 @@ func visibleSessionMessages(messages []providers.Message, toolFeedbackMaxArgsLen
 			// Pico web chat can persist both visible `message` tool output and a
 			// later plain assistant reply in the same turn. Hide only the fixed
 			// internal summary that marks handled tool delivery.
-			if !sessionMessageVisible(msg) {
-				continue
-			}
-
 			content := msg.Content
 			if assistantMessageInternalOnly(msg) {
 				if len(attachments) == 0 {
@@ -525,12 +521,17 @@ func visibleSessionMessages(messages []providers.Message, toolFeedbackMaxArgsLen
 				content = ""
 			}
 
-			transcript = append(transcript, sessionChatMessage{
+			chatMsg := sessionChatMessage{
 				Role:        "assistant",
 				Content:     content,
 				Media:       append([]string(nil), msg.Media...),
 				Attachments: attachments,
-			})
+			}
+			if !sessionChatMessageVisible(chatMsg) {
+				continue
+			}
+
+			transcript = append(transcript, chatMsg)
 		}
 	}
 
@@ -587,12 +588,11 @@ func sessionAttachmentURL(attachment providers.Attachment) (string, bool) {
 		return "", false
 	}
 	if strings.HasPrefix(ref, "media://") {
-		refID := strings.TrimSpace(strings.TrimPrefix(ref, "media://"))
+		// Persisted session history must only expose durable attachment locations.
-		if refID == "" {
+		// media:// refs depend on the live in-memory MediaStore and may stop
+		// resolving after a restart or cleanup, so omit them from reopened history.
 		return "", false
 	}
-		return "/pico/media/" + url.PathEscape(refID), true
-	}
 	return ref, true
 }
 

web/backend/api/session_test.go

@@ -218,7 +218,7 @@ func TestHandleGetSession_JSONLStorage(t *testing.T) {
 	}
 }
 
-func TestHandleGetSession_ExposesHandledToolAttachments(t *testing.T) {
+func TestHandleGetSession_HidesHandledToolAttachmentsBackedByMediaRefs(t *testing.T) {
 	configPath, cleanup := setupOAuthTestEnv(t)
 	defer cleanup()
 
@@ -260,16 +260,63 @@ func TestHandleGetSession_ExposesHandledToolAttachments(t *testing.T) {
 	}
 
 	var resp struct {
-		Messages []struct {
+		Messages []sessionChatMessage `json:"messages"`
-			Role        string `json:"role"`
+	}
-			Content     string `json:"content"`
+	if err := json.Unmarshal(rec.Body.Bytes(), &resp); err != nil {
-			Attachments []struct {
+		t.Fatalf("Unmarshal() error = %v", err)
-				Type        string `json:"type"`
+	}
-				URL         string `json:"url"`
+
-				Filename    string `json:"filename"`
+	if len(resp.Messages) != 1 {
-				ContentType string `json:"content_type"`
+		t.Fatalf("len(resp.Messages) = %d, want 1", len(resp.Messages))
-			} `json:"attachments"`
+	}
-		} `json:"messages"`
+	if resp.Messages[0].Role != "user" || resp.Messages[0].Content != "send me the report" {
+		t.Fatalf("message = %#v, want only user request", resp.Messages[0])
+	}
+}
+
+func TestHandleGetSession_ExposesHandledToolAttachmentsWithDurableURL(t *testing.T) {
+	configPath, cleanup := setupOAuthTestEnv(t)
+	defer cleanup()
+
+	dir := sessionsTestDir(t, configPath)
+	store, err := memory.NewJSONLStore(dir)
+	if err != nil {
+		t.Fatalf("NewJSONLStore() error = %v", err)
+	}
+
+	sessionKey := legacyPicoSessionPrefix + "attachment-history-durable"
+	for _, msg := range []providers.Message{
+		{Role: "user", Content: "send me the report"},
+		{
+			Role:    "assistant",
+			Content: handledToolResponseSummaryText,
+			Attachments: []providers.Attachment{{
+				Type:        "file",
+				URL:         "https://example.com/report.txt",
+				Filename:    "report.txt",
+				ContentType: "text/plain",
+			}},
+		},
+	} {
+		if err := store.AddFullMessage(nil, sessionKey, msg); err != nil {
+			t.Fatalf("AddFullMessage() error = %v", err)
+		}
+	}
+
+	h := NewHandler(configPath)
+	mux := http.NewServeMux()
+	h.RegisterRoutes(mux)
+
+	rec := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodGet, "/api/sessions/attachment-history-durable", nil)
+	mux.ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d, want %d, body=%s", rec.Code, http.StatusOK, rec.Body.String())
+	}
+
+	var resp struct {
+		Messages []sessionChatMessage `json:"messages"`
 	}
 	if err := json.Unmarshal(rec.Body.Bytes(), &resp); err != nil {
 		t.Fatalf("Unmarshal() error = %v", err)
@@ -289,8 +336,12 @@ func TestHandleGetSession_ExposesHandledToolAttachments(t *testing.T) {
 	if len(assistant.Attachments) != 1 {
 		t.Fatalf("len(assistant.Attachments) = %d, want 1", len(assistant.Attachments))
 	}
-	if assistant.Attachments[0].URL != "/pico/media/attachment-1" {
+	if assistant.Attachments[0].URL != "https://example.com/report.txt" {
-		t.Fatalf("attachment url = %q, want %q", assistant.Attachments[0].URL, "/pico/media/attachment-1")
+		t.Fatalf(
+			"attachment url = %q, want %q",
+			assistant.Attachments[0].URL,
+			"https://example.com/report.txt",
+		)
 	}
 	if assistant.Attachments[0].Filename != "report.txt" {
 		t.Fatalf("attachment filename = %q, want %q", assistant.Attachments[0].Filename, "report.txt")