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

ui/src/api/client.ts

@@ -0,0 +1,43 @@
+import type { Remote, Virtual, Artifact, OverviewStats, RemoteStatRow, HealthStatus, ProbeResult } from './types';
+
+const BASE = '';
+
+async function fetchJSON<T>(path: string, init?: RequestInit): Promise<T> {
+  const resp = await fetch(`${BASE}${path}`, {
+    ...init,
+    headers: { 'Content-Type': 'application/json', ...init?.headers },
+  });
+  if (!resp.ok) {
+    const text = await resp.text();
+    throw new Error(`${resp.status}: ${text}`);
+  }
+  if (resp.status === 204) return undefined as T;
+  return resp.json();
+}
+
+export const api = {
+  health: () => fetchJSON<HealthStatus>('/api/v2/health'),
+  stats: () => fetchJSON<OverviewStats>('/api/v2/stats'),
+  topRemotes: () => fetchJSON<RemoteStatRow[]>('/api/v2/stats/top-remotes'),
+
+  listRemotes: () => fetchJSON<Remote[]>('/api/v2/remotes'),
+  getRemote: (name: string) => fetchJSON<Remote>(`/api/v2/remotes/${name}`),
+
+  listVirtuals: () => fetchJSON<Virtual[]>('/api/v2/virtuals'),
+  getVirtual: (name: string) => fetchJSON<Virtual>(`/api/v2/virtuals/${name}`),
+
+  listObjects: (remote: string, page = 1, perPage = 50) =>
+    fetchJSON<Artifact[]>(`/api/v2/remotes/${remote}/objects?page=${page}&per_page=${perPage}`),
+
+  evictObject: (remote: string, path: string) =>
+    fetchJSON<void>(`/api/v2/remotes/${remote}/objects/${path}`, { method: 'DELETE' }),
+
+  flushRemoteCache: (remote: string) =>
+    fetchJSON<void>(`/api/v2/remotes/${remote}/cache`, { method: 'DELETE' }),
+
+  probe: (remote: string, path: string) =>
+    fetchJSON<ProbeResult>('/api/v2/probe', {
+      method: 'POST',
+      body: JSON.stringify({ remote, path }),
+    }),
+};