Adopt golib/pg for migrations and pool construction

artifactapi's schema was a ~180-line inline DDL blob re-executed on every
start, growing an ALTER TABLE ... IF NOT EXISTS line per change with nothing
recording what had run. golib/pg already owns that mechanic for the estate, so
move the SQL into a versioned, embedded set and let the library apply it.

- Depend on git.unkin.net/unkin/golib v0.1.0.
- Move the DDL verbatim to migrations/0001_init.sql, embedded via the new
  migrations package, and build the pool with pg.NewMigrated (LockName
  "artifactapi-migrations"). The runner adds a cluster-wide advisory lock the
  old blob never took, so replicas starting together queue instead of racing
  each other through the DDL.
- The live database has the schema but no schema_migrations, so its first start
  on this build re-runs 0001. Every statement is IF NOT EXISTS-guarded, so that
  run is a no-op landing only the tracking row; a container-backed test drops
  the row from a migrated database and asserts exactly that, and a static guard
  keeps future migrations additive and idempotent.
- Keep config.DatabaseDSN as the DSN source rather than pg.DSNFromEnv: the
  variable names match, but golib has no default user or database name, and
  artifactapi documents and ships DBUSER/DBNAME defaults of "artifacts". The
  deployed env var contract is unchanged.
- Guard the embedded set against migrations/ and pin the derived advisory key,
  so neither can drift unnoticed.
- Plumb GOPRIVATE=git.unkin.net for the first cross-repo Go dependency:
  exported by the Makefile, set in the Dockerfile and the woodpecker Go steps,
  documented in the README.

go.mod

@@ -3,6 +3,7 @@ module git.unkin.net/unkin/artifactapi
 go 1.25.9
 
 require (
+	git.unkin.net/unkin/golib v0.1.0
 	github.com/cavaliergopher/rpm v1.3.0
 	github.com/charmbracelet/bubbletea v1.3.10
 	github.com/charmbracelet/lipgloss v1.1.0
@@ -12,11 +13,11 @@ require (
 	github.com/klauspost/compress v1.19.2
 	github.com/minio/minio-go/v7 v7.2.0
 	github.com/redis/go-redis/v9 v9.20.0
-	github.com/testcontainers/testcontainers-go v0.42.0
-	github.com/testcontainers/testcontainers-go/modules/postgres v0.42.0
+	github.com/testcontainers/testcontainers-go v0.44.0
+	github.com/testcontainers/testcontainers-go/modules/postgres v0.44.0
 	github.com/testcontainers/testcontainers-go/modules/redis v0.42.0
 	github.com/ulikunitz/xz v0.5.16
-	golang.org/x/crypto v0.51.0
+	golang.org/x/crypto v0.54.0
 	golang.org/x/time v0.15.0
 	gopkg.in/yaml.v3 v3.0.1
 )
@@ -41,22 +42,22 @@ require (
 	github.com/cpuguy83/dockercfg v0.3.2 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/distribution/reference v0.6.0 // indirect
-	github.com/docker/go-connections v0.6.0 // indirect
+	github.com/docker/go-connections v0.7.0 // indirect
 	github.com/docker/go-units v0.5.0 // indirect
 	github.com/dustin/go-humanize v1.0.1 // indirect
-	github.com/ebitengine/purego v0.10.0 // indirect
+	github.com/ebitengine/purego v0.10.1 // indirect
 	github.com/erikgeiser/coninput v0.0.0-20211004153227-1c3628e74d0f // indirect
-	github.com/felixge/httpsnoop v1.0.4 // indirect
+	github.com/felixge/httpsnoop v1.1.0 // indirect
 	github.com/go-logr/logr v1.4.3 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
-	github.com/go-ole/go-ole v1.2.6 // indirect
+	github.com/go-ole/go-ole v1.3.0 // indirect
 	github.com/jackc/pgpassfile v1.0.0 // indirect
 	github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 // indirect
 	github.com/jackc/puddle/v2 v2.2.2 // indirect
 	github.com/klauspost/cpuid/v2 v2.2.11 // indirect
 	github.com/klauspost/crc32 v1.3.0 // indirect
 	github.com/lucasb-eyer/go-colorful v1.4.0 // indirect
-	github.com/lufia/plan9stats v0.0.0-20211012122336-39d0f177ccd0 // indirect
+	github.com/lufia/plan9stats v0.0.0-20260330125221-c963978e514e // indirect
 	github.com/magiconair/properties v1.8.10 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
 	github.com/mattn/go-localereader v0.0.1 // indirect
@@ -66,10 +67,10 @@ require (
 	github.com/minio/md5-simd v1.1.2 // indirect
 	github.com/moby/docker-image-spec v1.3.1 // indirect
 	github.com/moby/go-archive v0.2.0 // indirect
-	github.com/moby/moby/api v1.54.1 // indirect
-	github.com/moby/moby/client v0.4.0 // indirect
+	github.com/moby/moby/api v1.55.0 // indirect
+	github.com/moby/moby/client v0.5.0 // indirect
 	github.com/moby/patternmatcher v0.6.1 // indirect
-	github.com/moby/sys/sequential v0.6.0 // indirect
+	github.com/moby/sys/sequential v0.7.0 // indirect
 	github.com/moby/sys/user v0.4.0 // indirect
 	github.com/moby/sys/userns v0.1.0 // indirect
 	github.com/moby/term v0.5.2 // indirect
@@ -83,25 +84,25 @@ require (
 	github.com/power-devops/perfstat v0.0.0-20240221224432-82ca36839d55 // indirect
 	github.com/rivo/uniseg v0.4.7 // indirect
 	github.com/rs/xid v1.6.0 // indirect
-	github.com/shirou/gopsutil/v4 v4.26.3 // indirect
+	github.com/shirou/gopsutil/v4 v4.26.6 // indirect
 	github.com/sirupsen/logrus v1.9.4 // indirect
 	github.com/stretchr/testify v1.11.1 // indirect
 	github.com/tinylib/msgp v1.6.1 // indirect
-	github.com/tklauser/go-sysconf v0.3.16 // indirect
-	github.com/tklauser/numcpus v0.11.0 // indirect
+	github.com/tklauser/go-sysconf v0.4.0 // indirect
+	github.com/tklauser/numcpus v0.12.0 // indirect
 	github.com/xo/terminfo v0.0.0-20220910002029-abceb7e1c41e // indirect
 	github.com/yusufpapurcu/wmi v1.2.4 // indirect
 	github.com/zeebo/xxh3 v1.1.0 // indirect
 	go.opentelemetry.io/auto/sdk v1.2.1 // indirect
-	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.60.0 // indirect
-	go.opentelemetry.io/otel v1.41.0 // indirect
-	go.opentelemetry.io/otel/metric v1.41.0 // indirect
-	go.opentelemetry.io/otel/trace v1.41.0 // indirect
+	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.69.0 // indirect
+	go.opentelemetry.io/otel v1.44.0 // indirect
+	go.opentelemetry.io/otel/metric v1.44.0 // indirect
+	go.opentelemetry.io/otel/trace v1.44.0 // indirect
 	go.uber.org/atomic v1.11.0 // indirect
 	go.yaml.in/yaml/v3 v3.0.4 // indirect
-	golang.org/x/net v0.53.0 // indirect
-	golang.org/x/sync v0.20.0 // indirect
-	golang.org/x/sys v0.44.0 // indirect
-	golang.org/x/text v0.37.0 // indirect
+	golang.org/x/net v0.56.0 // indirect
+	golang.org/x/sync v0.22.0 // indirect
+	golang.org/x/sys v0.47.0 // indirect
+	golang.org/x/text v0.40.0 // indirect
 	gopkg.in/ini.v1 v1.67.2 // indirect
 )