Backs the schema added in 210d310 with SQLAlchemy 2.0 models.
- SessionFact: "What we know" facts with polymorphic source_ref pointing
at task-lane item UUIDs inside ai_sessions.pending_task_lane (not a FK
per Section 4.2).
- SessionSuggestedFix: AI-proposed resolutions with supersession tracking
and the full user_decision state machine.
- DraftTemplate: post-resolve templatization queue with promotion to
script_templates.
- AccountSettings: per-account JSONB preferences grab-bag with async
classmethod helpers — get_setting(db, account_id, key, default) reads
without creating, set_setting(db, account_id, key, value) upserts via
Postgres ON CONFLICT + jsonb `||` merge so existing keys are preserved.
Lazy row creation matches the Phase 1 design.
Column additions on existing models to mirror the migration:
- AISession: resolution_note_* / escalation_package_* / state_version
(the preview-cache-invalidation counter consumed by Phase 3).
- ScriptTemplate: source_session_id / source_user_id / source_ticket_ref
(provenance for templates promoted from DraftTemplate).
All four new models registered in app.models.__init__ and __all__.
TYPE_CHECKING-guarded relationship imports throughout, matching the
repo's existing model style.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Michael Chihlas
b49772f1a1