feat: IPv6 outbound rotation via curl --interface

- Add IPv6SourcePool for round-robin IP rotation
- fetchViaCurl: Bun.spawn + curl -6 --interface for source binding
- Auto-fallback to regular fetch when IPv6 connection fails
- Response decompression via --compressed flag
- Docker + GHCR build/deploy workflows
- 8 routable IPv6 addresses on VPS

CLAUDE.md

@@ -7,8 +7,50 @@ Key architecture facts:
 - Middleware stack: rate limiter, body limiter, structured logger, SSRF protection
 - WebSocket relay: bidirectional relay via `x-relay-target` header with `ws://` or `wss://`
 - Error classification: DNS errors -> 502, timeouts -> 504, SSRF blocks -> 403, rate limits -> 429
+- IPv6 support: dual-stack listen + outbound source rotation via `Bun.spawn` + `curl --interface`
 - The old Next.js `src/app/route.ts` still exists as a legacy file but is no longer the active entry point
 
+## IPv6 Configuration
+
+### Environment Variables
+
+| Variable | Default | Description |
+|----------|---------|-------------|
+| `HOST` | `::` | Bind address. Use `::` for dual-stack (IPv4+IPv6) |
+| `IPV6_SOURCES` | _(empty)_ | Comma-separated IPv6 source addresses for outbound rotation |
+
+### Setup
+
+1. Add IPv6 addresses to your interface:
+```bash
+ip -6 addr add 2001:df4:c140:1f::d6/128 dev eth0
+ip -6 addr add 2001:df4:c140:1f:ffff:ffff:ffff:ffff/128 dev eth0
+```
+
+2. Configure the proxy with IPv6 source rotation:
+```bash
+IPV6_SOURCES=2001:df4:c140:1f::d6,2001:df4:c140:1f:ffff:ffff:ffff:ffff bun run src/index.ts
+```
+
+### How It Works
+
+- **Listen**: Server binds to `::` (all IPv6 interfaces) with `ipv6Only: false` (dual-stack)
+- **Outbound**: When `IPV6_SOURCES` is configured, each outbound request rotates through the source addresses using `curl --interface <ipv6>`
+- **Failover**: Failed source addresses are automatically disabled after 3 consecutive failures
+
+### Source: `src/lib/ipv6-pool.ts`
+
+```typescript
+import { IPv6SourcePool } from "./lib/ipv6-pool";
+
+const pool = new IPv6SourcePool();
+pool.loadFromEnv(); // reads IPV6_SOURCES
+
+const source = pool.getNext(); // round-robin
+pool.markSuccess(source);      // reset failure count
+pool.markFailed(source);       // increment failure count
+```
+
 Default to using Bun instead of Node.js.
 
 - Use `bun <file>` instead of `node <file>` or `ts-node <file>`