feat(02-01): add migration infrastructure with golang-migrate and embedded SQL

- RunMigrations applies versioned SQL files via golang-migrate + embed.FS (iofs)
- ErrNoChange handled correctly - not treated as failure
- Migration 0001 creates full current schema with CREATE TABLE IF NOT EXISTS
- All three tables (updates, tags, tag_assignments) with acknowledged_at and ON DELETE CASCADE
- Uses database/sqlite sub-package (modernc.org/sqlite, no CGO)
- go mod tidy applied after adding dependencies

go.mod

@@ -2,9 +2,13 @@ module awesomeProject
 
 go 1.26
 
+require (
+	github.com/golang-migrate/migrate/v4 v4.19.1
+	modernc.org/sqlite v1.46.1
+)
+
 require (
 	github.com/dustin/go-humanize v1.0.1 // indirect
-	github.com/golang-migrate/migrate/v4 v4.19.1 // indirect
 	github.com/google/uuid v1.6.0 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
 	github.com/ncruces/go-strftime v1.0.0 // indirect
@@ -14,5 +18,4 @@ require (
 	modernc.org/libc v1.67.6 // indirect
 	modernc.org/mathutil v1.7.1 // indirect
 	modernc.org/memory v1.11.0 // indirect
-	modernc.org/sqlite v1.46.1 // indirect
 )