_maybe_inject_run_budget_wrapup() appends its wrap-up notice to the newest
role:"tool" message in place, with no _DB_PERSISTED_MARKER check. Its sibling,
_maybe_inject_iteration_budget_warning(), got exactly this guard added in the
same recent saga (turn_iteration_prep.py), with the comment "an older turn may
already be cached."
The reachability is structural, not an edge case: _maybe_inject_run_budget_wrapup
is only ever called from prepare_iteration(), at the START of the next iteration
-- strictly after tool_executor.py's _flush_session_db_after_tool_progress has
already flushed and marked the previous iteration's tool row persisted. So every
successful injection was mutating an already-persisted row: the wire request for
that turn carried the notice, but the durable transcript never did, diverging
replay from the live bytes and invalidating the provider's prompt-cache prefix
from that row onward.
Fix:
- Add the same _DB_PERSISTED_MARKER guard to _maybe_inject_run_budget_wrapup,
scoped to the specific tool row the reversed scan lands on (not just
messages[-1], since this function -- unlike its sibling -- scans backward for
the newest tool row rather than only checking the tail).
- Wire _maybe_inject_run_budget_wrapup into _flush_session_db_after_tool_progress
(pre-flush), mirroring exactly how _maybe_inject_iteration_budget_warning is
wired in both places. Without this, the guard alone would make the notice stop
firing in the common case, since prepare_iteration's call site almost always
hits an already-persisted row -- the pre-flush call site is what actually lets
it land in durable bytes.
Verified empirically: read the real call graph (tool_executor.py's three
_flush_session_db_after_tool_progress call sites cover every tool-completion
path) to confirm the guard's premise, then added an end-to-end test using a real
AIAgent + SessionDB that flushes and checks the persisted row for the notice
text. Mutation-verified: reverting the two production files drops exactly the 2
new/updated assertions (28 pass, 2 fail); reapplying restores green (30 passed).
Also ran the sibling iteration-budget-warning and /steer suites (71 passed) to
check for interaction regressions -- none.
511633be90