feat(parity): Item B Phase 1 substrate — live-delivery-v3 daemon-IPC attachment primitive

[mikemolinet]

Summary

Parity port of cueapi/cueapi#805 (merged 03:07:18Z). Mike Q-B ratify locked the ASYNC fire-accept dispatcher path 2026-05-12 ~00:38Z.

Design doc: https://trydock.ai/mike/live-delivery-v3-build-hub
Direction of parity: private-leads, OSS-lags.

What ships

5 new files + 3 modifications:

File	Type
`alembic/versions/035_agent_live_sessions_ipc_attachment.py`	NEW (renumbered from private's 063)
`app/schemas/ipc_attachment.py`	NEW (verbatim)
`app/services/ipc_attachment_service.py`	NEW (verbatim)
`app/routers/ipc_attachments.py`	NEW (verbatim)
`tests/test_ipc_attachments.py`	NEW (verbatim, 42 tests)
`app/models/agent_live_session.py`	MODIFIED (4 cols + 2 indexes + CHECK)
`app/routers/cues.py`	MODIFIED (_build_ipc_delivery_metadata helper + fire_cue stamping)
`app/main.py`	MODIFIED (registered router + reconcile_router)
`parity-manifest.json`	UPDATED

OSS-specific adaptations

• Migration renumbered: private 063 → OSS 035 (OSS alembic head was 034 at port-time; private chain at 064 post-rebase to cueapi-three's #804). down_revision adjusted accordingly. Documented in parity-manifest deviation note.
• All other files verbatim — OSS endpoint shapes are identical to private for Item B scope.

Schema (migration 035, backwards-compat zero-churn)

All 4 columns nullable/defaulted so existing v2.x rows continue unchanged:

• `ipc_session_token VARCHAR(32)` — daemon-issued ULID
• `transport VARCHAR(8) NOT NULL DEFAULT 'poll'` + CHECK IN `('ipc','poll')`
• `daemon_id UUID` — stable per-install Desktop daemon identity
• `last_reconciled_at TIMESTAMPTZ` — bumps on reconcile

Plus 2 indexes (`ix_agent_live_sessions_daemon`, `ix_agent_live_sessions_transport`).

Test plan

• Local: 42/42 OSS tests pass (`tests/test_ipc_attachments.py`)
• CI: green on cueapi-core
• parity-check action: no warnings (manifest updated with 3 new entries + 3 deviation note bumps)

🤖 Generated with Claude Code

[github-actions]

Parity check

This PR modifies files tracked in parity-manifest.json:

• alembic/versions/035_agent_live_sessions_ipc_attachment.py
• app/main.py
• app/routers/cues.py
• app/routers/ipc_attachments.py
• app/schemas/ipc_attachment.py
• app/services/ipc_attachment_service.py

Please confirm one of the following in a reply or PR description update:

1. The equivalent change has been applied to the private cueapi monorepo. Link the PR.
2. This change is OSS-only and does not need porting. Briefly explain why (e.g. "fixes a bug that only exists in the OSS build").
3. A follow-up issue has been filed to port the reverse direction. Link the issue.

This is a soft check — it does not block merge. The goal is visibility, not friction. See HOSTED_ONLY.md for the open-core policy.