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/profiles.yml

@@ -0,0 +1,22 @@
+school_compare:
+  target: dev
+  outputs:
+    dev:
+      type: postgres
+      host: "{{ env_var('PG_HOST', 'localhost') }}"
+      port: "{{ env_var('PG_PORT', '5432') | int }}"
+      user: "{{ env_var('PG_USER', 'postgres') }}"
+      password: "{{ env_var('PG_PASSWORD', 'postgres') }}"
+      dbname: "{{ env_var('PG_DATABASE', 'school_compare') }}"
+      schema: public
+      threads: 4
+
+    production:
+      type: postgres
+      host: "{{ env_var('PG_HOST') }}"
+      port: "{{ env_var('PG_PORT') | int }}"
+      user: "{{ env_var('PG_USER') }}"
+      password: "{{ env_var('PG_PASSWORD') }}"
+      dbname: "{{ env_var('PG_DATABASE') }}"
+      schema: public
+      threads: 4