Harden Codex retry and bridge recovery

[zvladru]

Summary

• Prevent fresh WebSocket retries for previous_response_id payloads that contain tool outputs without matching tool calls.
• Add stale HTTP bridge inflight-session cleanup diagnostics for drain/status paths.
• Normalize quota planner timestamps to naive UTC before database writes and comparisons.

Tests

• uv run pytest -q tests/unit/test_proxy_http_bridge.py::test_http_bridge_activity_snapshot_counts_pending_and_inflight_sessions tests/unit/test_proxy_http_bridge.py::test_http_bridge_activity_snapshot_cleans_stale_inflight_session tests/unit/test_proxy_http_bridge.py::test_get_or_create_http_bridge_session_inflight_wait_times_out tests/unit/test_proxy_http_bridge.py::test_get_or_create_http_bridge_session_capacity_wait_times_out tests/unit/test_proxy_utils.py::test_prepare_websocket_response_create_request_does_not_fresh_retry_tool_output_delta tests/unit/test_proxy_utils.py::test_prepare_websocket_response_create_request_captures_client_full_resend_anchor_replay tests/unit/test_proxy_utils.py::test_websocket_client_previous_response_full_resend_retry_rejects_tool_output_delta tests/unit/test_proxy_utils.py::test_websocket_client_previous_response_full_resend_retry_allows_self_contained_tool_history tests/unit/test_quota_planner.py

[zvladru]

Superseded by smaller focused PRs:

• fix(websocket): avoid fresh retry for tool-output deltas #1042 for the WebSocket tool-output fresh-retry fix
• fix(quota-planner): normalize datetimes before database use #1043 for quota-planner UTC timestamp normalization
• fix(http-bridge): clean stale inflight session futures #1044 for HTTP bridge stale inflight cleanup diagnostics

Closing this combined PR to keep review scope small.