style: apply gofmt

Estate-wide consolidation pass. golangci-lint v2 default set enables NO
formatter, so gofmt drift accumulated silently across the estate -- 8 repos
were carrying it, this one included. Same hole that let two files rot in
dma-cli until they were found by hand (dma-cli#12).

Mechanical and deterministic: `gofmt -w`, nothing hand-edited. Verified
before commit -- gofmt -l now reports 0, go build and go vet both pass.

Clears this repo to adopt the canonical .golangci.yml (infra
ci-templates/golangci.yml, infra#309 pattern) in a later wave.

ingestion/internal/vectorstore/pg_test.go

@@ -16,8 +16,9 @@ import (
 // reachable database.
 //
 // To run:
-//   BRAIN_PG_TEST_DSN='postgres://brain_app:pwd@127.0.0.1:5432/brain' \
-//   go test ./internal/vectorstore/... -run Integration
+//
+//	BRAIN_PG_TEST_DSN='postgres://brain_app:pwd@127.0.0.1:5432/brain' \
+//	go test ./internal/vectorstore/... -run Integration
 func dsn(t *testing.T) string {
 	t.Helper()
 	v := os.Getenv("BRAIN_PG_TEST_DSN")