Reported in Discord by @spherohero: `sessions recover --allow-partial` copied
20,817 of 20,824 message rows, then orphan cleanup deleted every one of them
because no session row was salvageable. Final output: 0 sessions, 0 messages.
The salvage worked and then threw the result away -- the exact opposite of
what --allow-partial exists to do.
_cleanup_partial_orphans() removed dependent rows whose session_id had no
matching sessions row. That is correct when a few sessions are lost; it is
catastrophic when the sessions b-tree is damaged worse than messages, which
is the common shape (sessions is small and hot, messages is large).
Reproduced exactly: 500 readable messages, unreadable sessions -> 500
copied, 500 removed, empty output.
Now _reconstruct_missing_sessions() runs FIRST, inside the same transaction,
synthesizing a minimal row per orphaned session_id (only id/source/started_at
are NOT NULL). started_at comes from the earliest surviving message.
Placeholders carry source='recovered' and an explicit title so a fabricated
session can never be mistaken for an original. Same repro now retains all
500 messages under 1 reconstructed session.
Reconstruction is reported as LOSS, not a clean recovery: session metadata
(title, model, timestamps, cost) is genuinely gone even though the
conversation text survived. loss_detected=True, partial=True,
complete=False, with a warning naming the counts.
Also fixes total_removed_or_relinked, which summed every dict value and would
now have counted retained messages as removed.
Sabotage-verified: removing the reconstruction call restores the wipe and
fails the test. 942 targeted tests green.
teknium1
d2e733e636