Feat/v3 go rewrite (#47)

Complete rewrite of ArtifactAPI from Python/FastAPI to Go as a single binary.

Core engine:
- 10 package providers: generic, docker, helm, pypi, npm, rpm, alpine,
  puppet, terraform, goproxy — each with built-in mutable patterns
- Content-addressable storage (SHA256 dedup across all remotes)
- Three-tier caching: Redis (TTL/locks) → S3/MinIO (blobs) → upstream
- Classifier with allowlist/blocklist per-remote (empty = allow all)
- Circuit breaker, conditional revalidation, stale-on-error
- Background garbage collection for orphaned blobs
- Access logging to PostgreSQL

API:
- v1 proxy endpoints (backwards compatible)
- v2 management API: CRUD remotes/virtuals, object browser, stats,
  health, SSE events, probe/test endpoint
- Virtual repos with index merging (Helm YAML + PyPI HTML)

Frontend (React + Vite, separate Dockerfile):
- Dashboard with stats, health indicators, top remotes
- Remotes list with type filter, remote detail with config/patterns
- Object browser with pagination and evict
- Test Remote page: probe any remote path, see headers/size/timing
- Virtuals page with expandable member lists

TUI (Bubble Tea):
- Dashboard, remotes list/detail, object browser, virtuals
- Vim-style navigation, artifactapi tui --endpoint <url>

Infrastructure:
- S3 client supports MinIO, Ceph RGW, AWS S3 (minio-go)
- PostgreSQL schema with migrations
- Docker Compose: API + UI + Postgres 17 + Redis 7 + MinIO
- Makefile with Go version check, build/test/lint/fmt/e2e targets
- Distroless Docker image (~15MB)

Testing:
- Unit tests for models, classifier, providers, mergers
- E2E tests with testcontainers-go (real Postgres/Redis/MinIO)

Terraform config:
- All 40 production remotes + helm virtual as HCL
- Provider repo: terraform-provider-artifactapi v0.0.1 (separate)

---------

Co-authored-by: Ben Vincent <ben@unkin.net>
Reviewed-on: #47

internal/database/remotes.go

@@ -0,0 +1,99 @@
+package database
+
+import (
+	"context"
+
+	"git.unkin.net/unkin/artifactapi/pkg/models"
+)
+
+const remoteCols = `name, package_type, base_url, description, username, password,
+	immutable_ttl, mutable_ttl, check_mutable,
+	patterns, blocklist, mutable_patterns, immutable_patterns,
+	ban_tags_enabled, ban_tags,
+	quarantine_enabled, quarantine_days, stale_on_error,
+	releases_remote, managed_by, created_at, updated_at`
+
+func scanRemote(scanner interface{ Scan(...any) error }, r *models.Remote) error {
+	return scanner.Scan(
+		&r.Name, &r.PackageType, &r.BaseURL, &r.Description, &r.Username, &r.Password,
+		&r.ImmutableTTL, &r.MutableTTL, &r.CheckMutable,
+		&r.Patterns, &r.Blocklist, &r.MutablePatterns, &r.ImmutablePatterns,
+		&r.BanTagsEnabled, &r.BanTags,
+		&r.QuarantineEnabled, &r.QuarantineDays, &r.StaleOnError,
+		&r.ReleasesRemote, &r.ManagedBy, &r.CreatedAt, &r.UpdatedAt,
+	)
+}
+
+func (db *DB) GetRemote(ctx context.Context, name string) (*models.Remote, error) {
+	row := db.Pool.QueryRow(ctx, `SELECT `+remoteCols+` FROM remotes WHERE name = $1`, name)
+	var r models.Remote
+	if err := scanRemote(row, &r); err != nil {
+		return nil, err
+	}
+	return &r, nil
+}
+
+func (db *DB) ListRemotes(ctx context.Context) ([]models.Remote, error) {
+	rows, err := db.Pool.Query(ctx, `SELECT `+remoteCols+` FROM remotes ORDER BY name`)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var remotes []models.Remote
+	for rows.Next() {
+		var r models.Remote
+		if err := scanRemote(rows, &r); err != nil {
+			return nil, err
+		}
+		remotes = append(remotes, r)
+	}
+	return remotes, rows.Err()
+}
+
+func (db *DB) CreateRemote(ctx context.Context, r *models.Remote) error {
+	_, err := db.Pool.Exec(ctx, `
+		INSERT INTO remotes (
+			name, package_type, base_url, description, username, password,
+			immutable_ttl, mutable_ttl, check_mutable,
+			patterns, blocklist, mutable_patterns, immutable_patterns,
+			ban_tags_enabled, ban_tags,
+			quarantine_enabled, quarantine_days, stale_on_error,
+			releases_remote, managed_by
+		) VALUES ($1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11,$12,$13,$14,$15,$16,$17,$18,$19,$20)
+	`,
+		r.Name, r.PackageType, r.BaseURL, r.Description, r.Username, r.Password,
+		r.ImmutableTTL, r.MutableTTL, r.CheckMutable,
+		r.Patterns, r.Blocklist, r.MutablePatterns, r.ImmutablePatterns,
+		r.BanTagsEnabled, r.BanTags,
+		r.QuarantineEnabled, r.QuarantineDays, r.StaleOnError,
+		r.ReleasesRemote, r.ManagedBy,
+	)
+	return err
+}
+
+func (db *DB) UpdateRemote(ctx context.Context, r *models.Remote) error {
+	_, err := db.Pool.Exec(ctx, `
+		UPDATE remotes SET
+			package_type=$2, base_url=$3, description=$4, username=$5, password=$6,
+			immutable_ttl=$7, mutable_ttl=$8, check_mutable=$9,
+			patterns=$10, blocklist=$11, mutable_patterns=$12, immutable_patterns=$13,
+			ban_tags_enabled=$14, ban_tags=$15,
+			quarantine_enabled=$16, quarantine_days=$17, stale_on_error=$18,
+			releases_remote=$19, managed_by=$20, updated_at=NOW()
+		WHERE name=$1
+	`,
+		r.Name, r.PackageType, r.BaseURL, r.Description, r.Username, r.Password,
+		r.ImmutableTTL, r.MutableTTL, r.CheckMutable,
+		r.Patterns, r.Blocklist, r.MutablePatterns, r.ImmutablePatterns,
+		r.BanTagsEnabled, r.BanTags,
+		r.QuarantineEnabled, r.QuarantineDays, r.StaleOnError,
+		r.ReleasesRemote, r.ManagedBy,
+	)
+	return err
+}
+
+func (db *DB) DeleteRemote(ctx context.Context, name string) error {
+	_, err := db.Pool.Exec(ctx, `DELETE FROM remotes WHERE name = $1`, name)
+	return err
+}