fix(proxy): reconcile continuity stack integration

[Komzpa]

Status

This remains a draft integration carrier for compatibility testing across focused proxy, compact, retry, migration, and continuity changes. It is not a reviewable single-concern pull request and must not be merged in its current form.

Current head: edafbadcece570e481808b2b59671b1a5d0bede4, based on e9273d209798a787eb58c9f24f8d0d643e381259.

The carrier was rebuilt from current main plus the current focused heads for:

• Soju06/codex-lb#1183 durable security-lineage persistence;
• Soju06/codex-lb#1457 inline tool-image compact recovery;
• Soju06/codex-lb#1235 compact tool-tail handling;
• Soju06/codex-lb#1383 Codex search preflight;
• Soju06/codex-lb#1384 accepted capacity retry; and
• Soju06/codex-lb#1402 native WebSocket close accounting.

Current main already contains the earlier focused pieces that this carrier used to embed separately, including Soju06/codex-lb#1353, Soju06/codex-lb#1389, Soju06/codex-lb#1418, and Soju06/codex-lb#1441.

Integration Behavior

The carrier combines the focused behaviors above with compatibility fixes that reconcile their contracts:

• retain durable response, side-effect, tool-call, and replay boundaries;
• retry model-capacity, overload, and transport failures only when the request is output-free and replay-safe;
• preserve previous-response, turn-state, session-header, hard-owner, and security-lineage continuity across HTTP bridge, direct stream, compact, and WebSocket paths;
• require security-work authorization for marked durable lineages without downgrading detached markers;
• preserve required compact tool tails, historical side-effect pairs, inline image elision context, and occurrence-aware tool identity; and
• keep native WebSocket receive closes account-neutral while preserving deferred settlement ownership.

The branch currently changes 64 files (+6034/-271 lines) relative to current main. That breadth is why this remains an integration carrier rather than a merge candidate.

Validation Status

Local validation at current head edafbadcece570e481808b2b59671b1a5d0bede4:

• uvx ruff check app tests .github/scripts openspec --exclude frontend passed.
• Carrier-owned OpenSpec changes validated individually with --strict: allow-compact-inline-image-elision, harden-compact-tool-tail-anchors, forward-codex-alpha-search, retry-model-capacity-errors, retry-server-is-overloaded, persist-security-lineage-markers, and preserve-websocket-drop-account-health.
• Focused aggregate pytest selection passed: 591 passed, 1032 deselected, with the current SQLAlchemy expression-index reflection warnings.
• Follow-up WebSocket/security retry slice passed: 345 passed, 566 deselected.
• The exact stale type-cast regression in test_relay_upstream_websocket_classified_stream_incomplete_drop_is_penalized passed after the aggregate compatibility commit.

Hosted CI for this head is running in workflow run 30338571892. Current-head Codex review has not yet been refreshed.

Maintainer Action

• Do not merge this pull request in its current form.
• Review, validate, and merge focused pull requests independently.
• Treat this branch as compatibility evidence for the current focused-head order only.

Non-Claims

• No component pull request is claimed merged, superseded, or ready because it appears in this carrier.
• This carrier does not establish a maintainer-approved merge order.
• Local aggregate validation does not substitute for green hosted CI, focused review state, or a fresh current-head Codex review.

[Soju06]

Triage audit: this carrier is by design not mergeable, and its compatibility evidence is now stale — the head (last commit 07-22) predates the current state of the focused PRs it embeds (e.g. #1383 was rebased on 07-28), and all six embedded PRs (#1183, #1457, #1235, #1383, #1384, #1402) remain open as the actual review surfaces. Suggest closing this PR to keep the triage queue focused on mergeable work; the branch remains available, and a fresh carrier can be rebuilt from current main + current focused heads if cross-PR integration testing is needed again. @Komzpa if you prefer to keep it, please refresh it against the current heads and keep the body's head reference accurate.