list_sessions_rich and _get_session_rich_row previously used SELECT s.*,
pulling the system_prompt TEXT blob on every row even for dashboard and
picker callers that never display it. On large databases this blob routinely
runs to tens of kilobytes per session, causing unnecessary B-tree I/O.
Add compact_rows=False param to both functions. When True, an explicit
column list omitting system_prompt is substituted for s.* in both the
simple and the recursive-CTE (order_by_last_active) query paths.
Default is False so all existing callers are unaffected.
Update dashboard and session-picker callers in web_server.py and
tui_gateway/server.py to pass compact_rows=True.
Add seven regression tests covering: omission of system_prompt, presence
of all metadata fields, both query paths, _get_session_rich_row, and
backward-compat default.
(cherry picked from commit c470cbd3042d95a62708cb5572118efd964f7699)
22eb1af23a