📢 1.6.0a11 — core session/wire refactor + DB migration 060 (back up your DB first)

[eous]

📢 Notice: 1.6.0a11 — core session/wire refactor + DB migration 060

Who this affects

Anyone tracking the experimental branch (main / 1.6.0a series).
Stable tracks (stable/1.5, stable/1.4) are not affected.

What's landing

1.6.0a11 ships a ~20,000-line refactor of the core session / wire-protocol
implementation, adding support for model providers with mid-conversation system
message support.

This unlocks:

• Proper metacognition / trajectory changes without custom system envelopes.
• Groundwork for upcoming work such as user-defined hooks.

Migration 060 (Alembic)

1.6.0a11 includes the 060 migration, which rewrites:

• Conversations (workstreams) → new internal storage format.
• Attachments → new attachment-by-reference schema.

⚠️ Action required — back up before upgrading

If you care about your saved conversations (workstreams), dump your database
before upgrading.

The migration is built to convert your data correctly to the new format, and it has
been tested against a local instance and a range of synthetic datasets. But because
it mutates existing data, a pre-upgrade backup is strongly recommended — it's
possible I've missed an edge case. Better safe than sorry.