Switch to timescaledb-ha image; enable PostGIS in migration

Migration 0001_positions.sql now runs CREATE EXTENSION IF NOT EXISTS
postgis alongside timescaledb. PostGIS isn't used in Phase 1 but enabling
it now means Phase 2's geofence engine doesn't need a separate migration
step. The deploy stack uses the timescale/timescaledb-ha:*-all image
which ships both extensions.

Integration test (pipeline.integration.test.ts) updated to use the same
timescale/timescaledb-ha:pg16.6-ts2.17.2-all image as the deploy stack.
Stock POSTGRES_USER/PASSWORD/DB env vars retained — if recent ha-image
revisions don't accept them, the test container will fail clearly on
first run with Docker, and we'll switch to the right env-var scheme.

test/pipeline.integration.test.ts

@@ -1,9 +1,11 @@
 /**
  * Integration test: end-to-end pipeline round-trip via testcontainers.
  *
- * Spins up Redis 7 and TimescaleDB (timescale/timescaledb:latest-pg16) containers,
- * runs the Processor migration, starts the consumer pipeline, publishes synthetic
- * Position records, and asserts the resulting rows in `positions`.
+ * Spins up Redis 7 and TimescaleDB-HA (timescale/timescaledb-ha:pg16.6-ts2.17.2-all,
+ * matching the deploy stack image) containers, runs the Processor migration,
+ * starts the consumer pipeline, publishes synthetic Position records, and asserts
+ * the resulting rows in `positions`. The `-all` image variant ships PostGIS too,
+ * so the migration's `CREATE EXTENSION IF NOT EXISTS postgis` succeeds.
  *
  * If Docker is unavailable (CI runner without Docker, local dev without Docker
  * Desktop), the suite skips — it does not fail the build. Docker availability is
@@ -139,9 +141,9 @@ beforeAll(async () => {
     return;
   }
 
-  // --- Step 2: start TimescaleDB container ------------------------------------
+  // --- Step 2: start TimescaleDB-HA container (same image as deploy stack) ---
   try {
-    pgContainer = await new GenericContainer('timescale/timescaledb:latest-pg16')
+    pgContainer = await new GenericContainer('timescale/timescaledb-ha:pg16.6-ts2.17.2-all')
       .withExposedPorts(5432)
       .withEnvironment({
         POSTGRES_USER: 'postgres',
@@ -152,7 +154,7 @@ beforeAll(async () => {
       .start();
   } catch (err) {
     console.warn(
-      `[pipeline.integration.test] Failed to start TimescaleDB container: ${String(err)} — skipping`,
+      `[pipeline.integration.test] Failed to start TimescaleDB-HA container: ${String(err)} — skipping`,
     );
     dockerAvailable = false;
     await redisContainer?.stop().catch(() => {});