feat(pipeline): add Meltano + dbt + Airflow ELT pipeline scaffold

Replaces the hand-rolled integrator with a production-grade ELT pipeline
using Meltano (Singer taps), dbt Core (medallion architecture), and
Apache Airflow (orchestration). Adds Typesense for search and PostGIS
for geospatial queries.

- 6 custom Singer taps (GIAS, EES, Ofsted, Parent View, FBIT, IDACI)
- dbt project: 12 staging, 5 intermediate, 12 mart models
- 3 Airflow DAGs (daily/monthly/annual schedules)
- Typesense sync + batch geocoding scripts
- docker-compose: add Airflow, Typesense; upgrade to PostGIS
- Portainer stack definition matching live deployment topology

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

pipeline/transform/dbt_project.yml

@@ -0,0 +1,28 @@
+name: school_compare
+version: "1.0.0"
+config-version: 2
+
+profile: school_compare
+
+model-paths: ["models"]
+macro-paths: ["macros"]
+test-paths: ["tests"]
+seed-paths: ["seeds"]
+target-path: "target"
+clean-targets: ["target", "dbt_packages"]
+
+models:
+  school_compare:
+    staging:
+      +materialized: view
+      +schema: staging
+    intermediate:
+      +materialized: view
+      +schema: intermediate
+    marts:
+      +materialized: table
+      +schema: marts
+
+seeds:
+  school_compare:
+    +schema: seeds