feat(capture): wire v1 sink router in production setup

[eli-r-ph]

Problem

This PR wires up the real production router when configured.

Changes

• Add v1_sink lifecycle handle to LifecycleHandles, registered conditionally when CAPTURE_V1_SINKS is non-empty
• Extract create_v1_sink_router() helper in setup.rs that builds KafkaProducer + KafkaSink + Router with rich anyhow::Context error propagation on each step
• Add v1_sink_router: Option<Arc<v1::sinks::Router>> to CaptureComponents
• Pass v1_sink_router as a parameter to router::router() instead of hardcoding None
• Flush the V1 sink router during graceful shutdown in server.rs (same pattern as legacy sink)
• Unit test for error propagation in create_v1_sink_router

The CAPTURE_V1_SINKS env var defaults to "" — no deployment behavior changes until a deploy explicitly sets the var. No consumer config is added.

How did you test this code?

Locally and in CI.

Publish to changelog?

N/A

🤖 Agent context

Eli planned, Claude coded, Eli collected paycheck ✅

[greptile-apps]

Prompt To Fix All With AI

Fix the following 1 code review issue. Work through them one at a time, proposing concise fixes.

---

### Issue 1 of 1
rust/capture/src/setup.rs:69-73
The final registration of `v1_sink` is the last use of `sink_opts`, so the `.clone()` is superfluous — `sink_opts` can be moved directly into `manager.register`. The clone allocates and drops immediately, which is unnecessary.

```suggestion
    let v1_sink = if !config.capture_v1_sinks.is_empty() {
        Some(manager.register("v1-sink", sink_opts))
    } else {
        None
    };
```

_{Reviews (1): Last reviewed commit: "feat(capture): wire v1 sink router in pr..." | Re-trigger Greptile}