Expand SnowBridge to own ingest + in-process transform; drop dbt

SnowBridge now owns machine-data ingest, in-process .NET transformation,
and direct writes to curated tables in Snowflake. Collapses the previous
ingest/transform split into a single service; no dbt, no external
orchestrator, no Snowflake landing tier. Keeps the in-house .NET pattern
consistent with ScadaBridge and OtOpcUa.

The "Snowflake dbt Transform Layer" roadmap workstream merges into
SnowBridge (7 → 6 workstreams); Year 2 canonical-state-based OEE moves
with it. Canonical model still has three surfaces — the third is
renamed from "dbt curated layer" to "SnowBridge curated layer in
Snowflake"; mechanics unchanged.

outputs/longform-spec.md

@@ -107,7 +107,7 @@ The Layered Architecture text diagram in `goal-state.md` (and any similar text d
 Markdown tables render as PDF tables with row-level borders and header-row emphasis. Tables that exceed one page split cleanly at row boundaries, with the header row repeated at the top of each continuation page. `document-skills:pdf` handles this natively.
 
 Specific large tables to expect:
-- [`../roadmap.md`](../roadmap.md) → **The grid** (7 workstreams × 3 years) — likely spans 2–3 pages
+- [`../roadmap.md`](../roadmap.md) → **The grid** (6 workstreams × 3 years) — likely spans 2–3 pages
 - [`../current-state/legacy-integrations.md`](../current-state/legacy-integrations.md) → per-row integration detail tables (one per integration)
 - [`../current-state/equipment-protocol-survey.md`](../current-state/equipment-protocol-survey.md) → field schema table, classification table, rollup views