improving async fastapi sqlmodel skill

docs/skills/async-fastapi-sqlmodel/references/index.md

@@ -1,6 +1,6 @@
 # FastAPI Async SQLAlchemy References Index
 
-Purpose: concept registry for modernization guidance used by this skill.
+Purpose: concept registry for the principles, mechanics, and implementation guidance used by this skill.
 
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@@ -13,13 +13,13 @@ Purpose: concept registry for modernization guidance used by this skill.
 | Transaction boundaries | [transactions.md](transactions.md) | adopted | mandatory | platform/backend | 2026-06-17 |
 | Implicit ORM I/O under asyncio | [implicit_io.md](implicit_io.md) | adopted | advisory | platform/backend | 2026-06-17 |
 | Observability and resilience | [observability.md](observability.md) | adopted | mandatory | platform/backend | 2026-06-17 |
-| SQLModel adoption and boundaries | [sqlmodel.md](sqlmodel.md) | adopted | advisory | platform/backend | 2026-06-26 |
+| SQLModel modeling and async boundaries | [sqlmodel.md](sqlmodel.md) | adopted | mandatory | platform/backend | 2026-07-26 |
 
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 ## How to Use This Folder
 
-- `SKILL.md` defines the planning workflow and migration procedure.
+- `SKILL.md` defines the explanatory workflow and shared mental model.
 - Each concept doc defines policy-level guidance for one concern.
 - Use the template in [template.md](template.md) for new concept docs.
 - Keep references source-linked and implementation snippets minimal.
@@ -30,4 +30,4 @@ Purpose: concept registry for modernization guidance used by this skill.
 
 - If a PR changes database lifecycle/session/ORM loading behavior, update the relevant concept file.
 - Keep `Status`, `Decision Level`, and `Last Reviewed` current.
-- Use `advisory` only when incremental rollout is intended; use `mandatory` for required runtime policy.
+- Use `advisory` for recommendations that depend on application context; use `mandatory` for required runtime policy.