test: production ingest E2E test suite with enhanced logging (#55)

## Summary
Production testing of ingest + embedding pipeline with api-gw integration.

## Root Cause
9 SQL migrations in `crates/mem-store/migrations/` not applied to production database.

Missing tables:
- `memory_entity`
- `memory_edge`
- `memory_edge_temporal`
- Vector embeddings tables
- And 15+ more schema objects

Evidence from logs:
```
WARN: Failed to save entity Docker:
      error returned from database: relation "memory_entity" does not exist
```

## Deliverables
- `test_prod_ingest_real.sh` - Full E2E test against K8s + api-gw
- `apply_migrations.sh` - Manual schema migration (backup)
- `collect_prod_logs.sh` - Pod log collection before/after
- `run_production_test.sh` - Test orchestrator
- `tests/integration_ingest_with_gw.rs` - Integration test
- `tests/unit_ingest_logging.rs` - Unit tests for extraction
- Enhanced logging in `ingest_worker.rs` - Per-record event tracking

## Next Steps
1. Trigger "DB Migration" workflow in Forgejo Actions
2. This applies all 9 migrations from `crates/mem-store/migrations/`
3. Pod restart (automatic)
4. Re-run E2E test - should pass completely

**ETA:** ~15 minutes (3-5 min migrations + 2 min restart + verification)

## How to Test Locally
```bash
./test_prod_ingest_real.sh --verbose
```

Requires:
- kubectl access to poimen namespace
- Port-forwarding to memory-service

---------

Co-authored-by: rock <[email protected]>
Reviewed-on: #55
Co-authored-by: poimen <[email protected]>

crates/mem-core/src/optimizer/builtin.rs

@@ -152,11 +152,11 @@ impl FormatHandler for CsvFormatter {
 
     async fn format(&self, result: &OptimizationResult) -> Result<Vec<u8>, String> {
         let output = format!(
-            "{},{},{},{}\n",
+            "{},{},{},{:.2}\n",
             escape_csv(&result.plugin),
             result.original.len(),
             result.optimized.len(),
-            format!("{:.2}", result.ratio)
+            result.ratio
         );
         Ok(output.into_bytes())
     }