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/README.md

@@ -86,7 +86,7 @@ Diagrams are **hand-drawn source files** committed to [`diagrams/`](diagrams/),
 The spec currently references two diagrams:
 
 - `diagrams/architecture-layers.png` — the 4-layer goal-state architecture stack (Equipment → OtOpcUa → SCADA → ScadaBridge → Enterprise IT), with the IT↔OT boundary marked.
-- `diagrams/end-to-end-flow.png` — the left-to-right data flow for one tag, matching `goal-state.md` line 77 exactly (Equipment → OtOpcUa → System Platform/Ignition → ScadaBridge → Redpanda → SnowBridge → Snowflake → dbt → Power BI).
+- `diagrams/end-to-end-flow.png` — the left-to-right data flow for one tag (Equipment → OtOpcUa → System Platform/Ignition → ScadaBridge → Redpanda → SnowBridge → Snowflake → Power BI). SnowBridge owns ingest + in-process transform; no separate dbt hop.
 
 Both are **not yet authored.** On first regeneration, Claude will either author the `.mmd` sources and attempt to render them, or flag this as a manual step in the run log. Until the PNGs exist, the corresponding slides (slides 8 and 9 in the deck) will have placeholder boxes.