# SQ-015: SDK Consumer

**Status:** `[ ] TODO`
**Blocked by:** SQ-014, SQ-012
**Priority:** Medium

## Description

Ergonomic Rust consumer client in sq-sdk. Wraps the server-streaming Subscribe RPC with poll-based interface and auto-commit support.

## Files to Create/Modify

- `crates/sq-sdk/src/consumer.rs` - Consumer with poll loop and auto-commit

## Consumer API

```rust
pub struct ConsumerConfig {
    pub server_addresses: Vec<String>,
    pub consumer_group: String,
    pub topics: Vec<String>,
    pub auto_commit: bool,
    pub auto_commit_interval_ms: u64,
    pub max_poll_records: u32,
}

pub struct Consumer { /* ... */ }

impl Consumer {
    pub async fn connect(config: ConsumerConfig) -> Result<Self, SqError>;
    pub async fn poll(&mut self) -> Result<Vec<ConsumedMessage>, SqError>;
    pub async fn commit(&self, topic: &str, partition: u32, offset: u64) -> Result<(), SqError>;
}
```

## Acceptance Criteria

- [ ] End-to-end: produce 100 messages with Producer, consume all with Consumer
- [ ] Auto-commit: consumed offsets are committed after interval
- [ ] Manual commit: explicit commit stores offset
- [ ] Poll returns empty vec when no new messages (non-blocking)
- [ ] Consumer group: two consumers resume from committed offset