Preserve imported conversation dates and show provider logos

docs/engineering/external_conversation_import.md

@@ -48,6 +48,13 @@ The capability has five layers:
 3. Only ordinary user-visible human and assistant text is projected into the
    actor-scoped chat-history store. The projection carries external actor and
    event provenance and is marked read-only.
+   Recorded message dates are preserved. Missing message dates use the source
+   file's last-modified time, labelled `source_file_modified`; the original
+   source timestamp remains null and import time is recorded separately.
+   Re-import repairs older import-time fallbacks only for unchanged events.
+   Known providers use local Codex, Claude Code, Copilot and Gemini brand assets
+   in conversation rows and assistant avatars; these do not imply a registered
+   Von participant identity.
 4. Continue creates a new native conversation with a lineage receipt and a
    copy of the visible history. The source snapshot remains unchanged.
 5. Machine-wide discovery and execution use a persisted batch/item controller.

src/backend/services/chat_history_service.py

@@ -4853,6 +4853,7 @@ def _event_fingerprint(entry: Mapping[str, Any]) -> str:
         }
 
     divergence: Dict[str, Any] | None = None
+    corrected_fallback_timestamp_count = 0
     appended_history = prepared_history
     action = "new"
     if existing is not None:
@@ -4920,13 +4921,40 @@ def _event_fingerprint(entry: Mapping[str, Any]) -> str:
         else:
             action = "refreshed"
 
+        # A missing source timestamp is part of the event fingerprint; its
+        # display fallback is not. Repair only verified, unchanged events.
+        if not divergence:
+            repaired_history = []
+            for entry in existing_history:
+                incoming = incoming_by_id.get(entry.get("external_event_id"))
+                if (
+                    incoming is not None
+                    and "external_source_timestamp_utc" in entry
+                    and entry["external_source_timestamp_utc"] is None
+                    and incoming.get("external_timestamp_source") == "source_file_modified"
+                    and _coerce_datetime(incoming.get("timestamp")) is not None
+                    and (
+                        entry.get("timestamp") != incoming["timestamp"]
+                        or entry.get("external_timestamp_source") != "source_file_modified"
+                    )
+                ):
+                    entry = {
+                        **entry,
+                        "timestamp": incoming["timestamp"],
+                        "external_timestamp_source": "source_file_modified",
+                    }
+                    corrected_fallback_timestamp_count += 1
+                repaired_history.append(entry)
+            existing_history = repaired_history
+
     combined_history = [*existing_history, *appended_history]
     stored_manifest["synchronisation"] = {
         "schema_version": "external_conversation_synchronisation.v1",
         "action": action,
         "checked_at_utc": now.isoformat(),
         "appended_message_count": len(appended_history),
         "retained_message_count": len(existing_history),
+        "corrected_fallback_timestamp_count": corrected_fallback_timestamp_count,
         "divergence": divergence,
     }
     search_segments = [
@@ -4974,7 +5002,13 @@ def _event_fingerprint(entry: Mapping[str, Any]) -> str:
         query[f"{EXTERNAL_CONVERSATION_IMPORT_FIELD}.package_sha256"] = (
             existing_manifest.get("package_sha256")
         )
-        if appended_history:
+        if corrected_fallback_timestamp_count:
+            # Keep the same package compare-and-swap and avoid conflicting
+            # $push/$set updates to the history array.
+            set_fields["history"] = combined_history
+            set_fields["created_at"] = first_message_at
+            set_on_insert.pop("created_at", None)
+        elif appended_history:
             update["$push"] = {"history": {"$each": appended_history}}
     try:
         result = chat_history_coll.update_one(
@@ -5041,6 +5075,7 @@ def _event_fingerprint(entry: Mapping[str, Any]) -> str:
         "action": action,
         "session_id": session_id,
         "appended_message_count": len(appended_history),
+        "corrected_fallback_timestamp_count": corrected_fallback_timestamp_count,
         "divergence": divergence,
         "canonical_read_back": {
             "session_id": session_id,

src/backend/services/external_conversation_import_service.py

@@ -30,7 +30,7 @@
 
 
 EXTERNAL_CONVERSATION_PACKAGE_SCHEMA_VERSION = "external_conversation_package.v1"
-EXTERNAL_CONVERSATION_PARSER_VERSION = "2026-09-16.2"
+EXTERNAL_CONVERSATION_PARSER_VERSION = "2026-09-16.3"
 EXTERNAL_CONVERSATION_ORIGIN_KIND = "external_conversation_import"
 EXTERNAL_CONVERSATION_LINEAGE_SCHEMA_VERSION = "conversation_lineage.v1"
 MAX_EXTERNAL_CONVERSATION_SOURCE_BYTES = 32 * 1024 * 1024
@@ -1460,6 +1460,8 @@ def parse_external_conversation_file(
 
 def _history_projection(
     package: ExternalConversationPackage,
+    *,
+    source_file_modified_at: datetime,
 ) -> tuple[list[dict[str, Any]], dict[str, Any]]:
     history: list[dict[str, Any]] = []
     total_chars = 0
@@ -1489,7 +1491,10 @@ def _history_projection(
             {
                 "role": event.source_role,
                 "content": projected,
-                "timestamp": timestamp or datetime.now(timezone.utc),
+                "timestamp": timestamp or source_file_modified_at,
+                "external_timestamp_source": (
+                    "source_message" if timestamp else "source_file_modified"
+                ),
                 "external_event_id": event.event_id,
                 "external_event_kind": event.event_kind,
                 "external_source_role": event.source_role,
@@ -1621,7 +1626,10 @@ def import_external_conversation_file(
         source_account=package.source_account,
         source_workspace=package.source_workspace,
     )
-    history, projection_report = _history_projection(package)
+    source_file_modified_at = datetime.fromtimestamp(path.stat().st_mtime, timezone.utc)
+    history, projection_report = _history_projection(
+        package, source_file_modified_at=source_file_modified_at
+    )
     if not history:
         raise ExternalConversationImportError(
             "The source contains no user-visible human or assistant messages.",
@@ -1717,6 +1725,7 @@ def import_external_conversation_file(
         "parser_version": package.parser_version,
         "source_created_at_utc": package.source_created_at_utc,
         "source_updated_at_utc": package.source_updated_at_utc,
+        "source_file_modified_at_utc": source_file_modified_at.isoformat(),
         "parent_conversation_id": package.parent_conversation_id,
         "raw_document_concept_id": raw_document_concept_id,
         "raw_file_copy_concept_id": raw_record_result.get("file_copy_concept_id"),

src/frontend/web/von_interface/static/images/providers/OCTICONS-LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 GitHub Inc.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

src/frontend/web/von_interface/static/images/providers/README.md

@@ -0,0 +1,10 @@
+# Imported conversation provider logos
+
+Used only to identify the source of imported conversations. Marks belong to their respective owners; they do not indicate endorsement. Assets are served locally.
+
+Retrieved 16 September 2026:
+
+- `codex.png`: unmodified Codex app mark bundled with OpenAI VS Code extension `openai.chatgpt-26.908.40401-darwin-arm64`, asset `codex-app-ga-logo-3e5209898ca3.png`.
+- `claude.svg`: https://claude.ai/favicon.svg
+- `copilot.svg`: https://raw.githubusercontent.com/primer/octicons/main/icons/copilot-24.svg (GitHub Octicons, MIT; see `OCTICONS-LICENSE`).
+- `gemini.svg`: https://www.gstatic.com/lamda/images/gemini_sparkle_aurora_33f86dc0c0257da337c63.svg, linked by https://gemini.google.com/.

src/frontend/web/von_interface/static/js/chatTab.js

@@ -10,6 +10,7 @@ import { createChatSteeringControls } from './components/chatSteeringControls.js
 import { directConversationRows, activeMessageConversationId, showChatConversation, resetConversationCatalogue, renderMessageConversationRow, mountCatalogueControls, initialiseConversationCatalogue, selectMessageConversation, filterCatalogueRows, catalogueSearchActive, rankCatalogueSearchRows } from './components/conversationCatalogue.js';
 import { catalogueHasMore } from './components/conversationCatalogue.js';
 import { profileButton, participantAvatar, participantIdentityAvatar } from './components/participantProfile.js';
+import { importedConversationAvatar } from './components/importedConversationAvatar.js';
 import { setButtonLabel } from './utils/buttonLabel.js';
 import { createConversationTray } from './components/conversationTray.js';
 import { CONVERSATION_LAYOUT_KEY, CONVERSATION_LAYOUT_KEYS, CONVERSATION_NARROW_QUERY, loadConversationLayoutPreferences, normaliseConversationLayout, saveConversationLayoutPreference } from './utils/conversationLayoutPreferences.js';
@@ -27535,7 +27536,9 @@ function renderChatSessionTabs(sessions, activeSessionId) {
 
         const header = document.createElement('span');
         header.className = 'chat-session-tab-header';
-        header.append(participantAvatar({ display_name: session.external_conversation ? displayName : 'Von', avatar_url: session.external_conversation ? null : '/static/VonImageBig.png' }));
+        header.append(session.external_conversation
+            ? importedConversationAvatar(session.external_conversation.provider, displayName, { sidebar: true })
+            : participantAvatar({ display_name: 'Von', avatar_url: '/static/VonImageBig.png' }));
 
         const pinToggle = document.createElement('button');
         pinToggle.type = 'button';
@@ -38369,10 +38372,7 @@ function appendMessage(sender, message, turnId, hasLlmDebug = false, isHistory =
             if (options.contributionTimestamp || timestampStr) messageContainer.dataset.contributionTimestamp = options.contributionTimestamp || timestampStr;
             let assistantAvatar;
             if (externalActor) {
-                assistantAvatar = document.createElement('span');
-                assistantAvatar.className = 'chat-imported-actor-avatar';
-                assistantAvatar.textContent = String(sender || 'Agent').trim().slice(0, 1).toUpperCase() || 'A';
-                assistantAvatar.setAttribute('aria-label', `${sender} (imported actor)`);
+                assistantAvatar = importedConversationAvatar(externalActor.source_actor_id, sender);
             } else {
                 assistantAvatar = document.createElement('img');
                 assistantAvatar.src = '/static/VonImageBig.png';

src/frontend/web/von_interface/static/js/components/importedConversationAvatar.js

@@ -0,0 +1,27 @@
+const PROVIDERS = {
+    codex: { label: 'Codex', file: 'codex.png' },
+    claude_code: { label: 'Claude Code', file: 'claude.svg' },
+    copilot: { label: 'GitHub Copilot', file: 'copilot.svg' },
+    gemini: { label: 'Gemini', file: 'gemini.svg' }
+};
+
+// Provider branding describes the imported source, not a verified Von identity.
+export function importedConversationAvatar(providerOrActor, displayName, { sidebar = false } = {}) {
+    const provider = String(providerOrActor || '').split(':')[0];
+    const brand = Object.hasOwn(PROVIDERS, provider) ? PROVIDERS[provider] : null;
+    const avatar = document.createElement('span');
+    avatar.className = sidebar ? 'participant-avatar imported-provider-avatar' : 'chat-imported-actor-avatar imported-provider-avatar';
+    avatar.setAttribute('role', 'img');
+    avatar.setAttribute('aria-label', `${brand?.label || displayName || 'Agent'} (imported)`);
+    avatar.title = `${brand?.label || displayName || 'Agent'} · Imported conversation`;
+    avatar.textContent = String(displayName || brand?.label || 'Agent').trim().slice(0, 1).toUpperCase();
+    if (brand) {
+        const image = document.createElement('img');
+        image.src = `/static/images/providers/${brand.file}`;
+        image.alt = '';
+        image.addEventListener('load', () => { avatar.classList.add('has-provider-logo'); });
+        image.addEventListener('error', () => { image.remove(); avatar.classList.remove('has-provider-logo'); });
+        avatar.append(image);
+    }
+    return avatar;
+}

src/frontend/web/von_interface/static/styles.css

@@ -8415,6 +8415,27 @@ body[data-active-tab="settingsTab"] .tab-content-area {
     font-weight: 700;
 }
 
+.imported-provider-avatar {
+    position: relative;
+    overflow: hidden;
+}
+
+.imported-provider-avatar.has-provider-logo {
+    color: transparent;
+    background: #fff;
+}
+
+.imported-provider-avatar img {
+    position: absolute;
+    inset: 0;
+    width: 100%;
+    height: 100%;
+    padding: 4px;
+    box-sizing: border-box;
+    object-fit: contain;
+    background: #fff;
+}
+
 .external-conversation-bulk-import {
     display: flex;
     align-items: center;