fix: show cron sessions in project filter

CHANGELOG.md

@@ -3,6 +3,10 @@
 
 ## [Unreleased]
 
+### Fixed
+
+- Cron sessions assigned to the dedicated Cron Jobs project now remain hidden from the default sidebar while still appearing when that project chip is selected.
+
 ## [v0.51.152] — 2026-05-28 — Release DX (stage-batch34 — single-PR optional gateway-backed browser chat)
 
 ### Added

api/models.py

@@ -2228,6 +2228,38 @@ def _is_intentionally_background_sidebar_session(session: dict) -> bool:
     return source == 'cron' or sid.startswith('cron_')
 
 
+def _include_project_hidden_background_sidebar_sessions(
+    candidates: list[dict],
+    visible: list[dict],
+) -> list[dict]:
+    """Keep project-assigned background sessions addressable by project chips.
+
+    Cron sessions stay hidden from the default sidebar, but if they have a
+    project assignment they must still be present in the client cache so the
+    dedicated project chip can reveal them (#3019).
+    """
+    visible_ids = {
+        str(session.get('session_id'))
+        for session in visible
+        if session.get('session_id')
+    }
+    out = list(visible)
+    for session in candidates:
+        sid = str(session.get('session_id') or '')
+        if not sid or sid in visible_ids:
+            continue
+        if not _is_intentionally_background_sidebar_session(session):
+            continue
+        if not session.get('project_id'):
+            continue
+        if _sidebar_message_count(session) <= 0:
+            continue
+        row = dict(session)
+        row['default_hidden'] = True
+        out.append(row)
+    return out
+
+
 def _preserve_messageful_sidebar_discoverability(
     candidates: list[dict],
     visible: list[dict],
@@ -2503,8 +2535,10 @@ def all_sessions(diag=None):
                 and not s.get('worktree_path')
             )]
             result = _prefer_fuller_snapshots_for_sidebar(result)
-            visible_result = [s for s in result if not _hide_from_default_sidebar(s)]
-            result = _preserve_messageful_sidebar_discoverability(result, visible_result)
+            sidebar_candidates = result
+            visible_result = [s for s in sidebar_candidates if not _hide_from_default_sidebar(s)]
+            result = _preserve_messageful_sidebar_discoverability(sidebar_candidates, visible_result)
+            result = _include_project_hidden_background_sidebar_sessions(sidebar_candidates, result)
             _strip_sidebar_internal_flags(result)
             # Backfill: sessions created before Sprint 22 have no profile tag.
             # Attribute them to 'default' so the client profile filter works correctly.
@@ -2542,8 +2576,10 @@ def all_sessions(diag=None):
         and not getattr(s, 'worktree_path', None)
     )]
     result = _prefer_fuller_snapshots_for_sidebar(result)
-    visible_result = [s for s in result if not _hide_from_default_sidebar(s)]
-    result = _preserve_messageful_sidebar_discoverability(result, visible_result)
+    sidebar_candidates = result
+    visible_result = [s for s in sidebar_candidates if not _hide_from_default_sidebar(s)]
+    result = _preserve_messageful_sidebar_discoverability(sidebar_candidates, visible_result)
+    result = _include_project_hidden_background_sidebar_sessions(sidebar_candidates, result)
     _strip_sidebar_internal_flags(result)
     for s in result:
         if not s.get('profile'):

static/sessions.js

@@ -3285,7 +3285,9 @@ function renderSessionListFromCache(){
   // in _profiles_match, and a strict-equality client filter would reject those
   // rows incorrectly. So we trust the wire data and skip the redundant client
   // filter entirely.
-  const profileFiltered=sourceFiltered;
+  const profileFiltered=sourceFiltered.filter(s=>
+    !s.default_hidden||(_activeProject&&_activeProject!==NO_PROJECT_FILTER&&s.project_id===_activeProject)
+  );
   // Filter by active project. NO_PROJECT_FILTER sentinel asks for sessions
   // with no project_id; otherwise filter to the matching project_id, or
   // pass through when no filter is active.

tests/test_issue3019_cron_project_sessions.py

@@ -0,0 +1,44 @@
+"""Regression tests for #3019 cron sessions under the Cron Jobs project."""
+
+
+def test_project_assigned_cron_rows_are_returned_but_default_hidden():
+    from api.models import _include_project_hidden_background_sidebar_sessions
+
+    visible = [
+        {"session_id": "webui-1", "title": "Normal", "message_count": 1, "project_id": None},
+    ]
+    candidates = visible + [
+        {
+            "session_id": "cron_visible",
+            "source_tag": "cron",
+            "title": "Cron output",
+            "message_count": 2,
+            "project_id": "cron-project",
+        },
+        {
+            "session_id": "cron_unassigned",
+            "source_tag": "cron",
+            "title": "Cron output",
+            "message_count": 2,
+            "project_id": None,
+        },
+        {
+            "session_id": "cron_empty",
+            "source_tag": "cron",
+            "title": "Cron output",
+            "message_count": 0,
+            "project_id": "cron-project",
+        },
+    ]
+
+    rows = _include_project_hidden_background_sidebar_sessions(candidates, visible)
+
+    by_id = {row["session_id"]: row for row in rows}
+    assert set(by_id) == {"webui-1", "cron_visible"}
+    assert by_id["cron_visible"]["default_hidden"] is True
+
+
+def test_session_list_project_filter_can_reveal_default_hidden_cron_rows():
+    src = ( __import__("pathlib").Path(__file__).parent.parent / "static" / "sessions.js").read_text(encoding="utf-8")
+
+    assert "!s.default_hidden||(_activeProject&&_activeProject!==NO_PROJECT_FILTER&&s.project_id===_activeProject)" in src

tests/test_sidebar_first_turn_visibility.py

@@ -111,7 +111,7 @@ class TestSidebarFirstTurnVisibility:
     def test_backend_index_filter_keeps_pending_first_turn_sessions(self):
         src = read("api/models.py")
         index_filter_start = src.index("# Hide empty Untitled sessions from the UI entirely")
-        index_filter_end = src.index("result = [s for s in result if not _hide_from_default_sidebar", index_filter_start)
+        index_filter_end = src.index("visible_result = [s for s in sidebar_candidates if not _hide_from_default_sidebar", index_filter_start)
         index_filter = src[index_filter_start:index_filter_end]
         assert "has_pending_user_message" in index_filter, (
             "The index-path empty-session filter must exempt pending first-turn sessions, "