PR #2053 added worktree-backed session creation. PR #2041 (shipped in
v0.51.42) added state.db sidecar reconciliation that rebuilds a missing
<sid>.json sidecar from the canonical state.db row when the JSON file is
gone (failed save, manual rm, restore-from-backup with mismatched dirs).
The two interact silently. `_state_db_row_to_sidecar()` was hard-coding
`'workspace': ''` and never propagating the four worktree_* fields from
the row to the rebuilt sidecar dict. So a worktree-backed session that
loses its sidecar and gets rebuilt from state.db:
- loses `worktree_path` → matches the empty-session sidebar filter at
`api/models.py:1067/1107` (which spares worktree-backed empty sessions
via `not s.get('worktree_path')`) → session disappears from the
sidebar even though the worktree directory still exists on disk.
- loses `workspace` → downstream tools (terminal panels, file pickers
that use `s.workspace`) operate on empty string instead of the original
worktree path.
- always reports `message_count == 0` → contributes to the empty-session
filter even for sessions that have messages in `state.db.messages`.
Fix:
1. `_read_state_db_missing_sidecar_rows()` SELECT now includes
`workspace, worktree_path, worktree_branch, worktree_repo_root,
worktree_created_at, message_count` (each gated by
`_sql_optional_col()` so older state.db schemas without those columns
continue to work — recovery degrades gracefully rather than 500ing).
2. `_state_db_row_to_sidecar()` propagates each field. workspace comes
from the row if it's a string, otherwise '' (matching pre-fix behavior
for non-worktree sessions). message_count comes from the row if
it's an int, otherwise falls back to `len(messages)` so the rebuilt
sidecar always has a coherent count.
3 new regression tests in tests/test_state_db_worktree_recovery.py
exercise:
- worktree session with messages → all four worktree_* fields preserved.
- non-worktree session → worktree_* fields all None (no spurious
propagation), workspace=''.
- empty worktree session (the worst case) → confirms the rebuilt sidecar
does NOT match the empty-session-exempt filter, so it stays visible
in the sidebar.
Caught by Opus advisor during stage-337 review (the cross-PR interaction
between #2053 and the previously-shipped #2041 wasn't exercised by either
PR's individual test suite).
