## MODIFIED Requirements

### Requirement: Connection pool status in performance detail
The performance-detail API SHALL include `db_pool` section with `status` (checked_out, checked_in, overflow, max_capacity, saturation, slow_query_active, slow_query_waiting) from `get_pool_status()` and `config` (pool_size, max_overflow, pool_timeout, pool_recycle) from `get_pool_runtime_config()`.

#### Scenario: Pool status retrieved
- **WHEN** the API is called
- **THEN** `db_pool.status` SHALL contain current pool utilization metrics including `slow_query_active` and `slow_query_waiting`, and `db_pool.config` SHALL contain the pool configuration values

#### Scenario: Saturation calculation
- **WHEN** the pool has 8 checked_out connections and max_capacity is 30
- **THEN** saturation SHALL be reported as approximately 26.7%

#### Scenario: Slow query waiting included
- **WHEN** 2 threads are waiting for the slow query semaphore
- **THEN** `db_pool.status.slow_query_waiting` SHALL be 2

## ADDED Requirements

### Requirement: Slow-path query latency included in QueryMetrics
The `read_sql_df_slow()` and `read_sql_df_slow_iter()` functions SHALL call `record_query_latency()` with the total elapsed time upon completion, ensuring P50/P95/P99 percentiles reflect queries from all paths (pooled and slow/direct).

#### Scenario: Slow query latency recorded
- **WHEN** `read_sql_df_slow()` completes a query in 8.5 seconds
- **THEN** `record_query_latency(8.5)` SHALL be called and the value SHALL appear in subsequent `get_percentiles()` results

#### Scenario: Slow iter latency recorded
- **WHEN** `read_sql_df_slow_iter()` completes streaming in 45 seconds
- **THEN** `record_query_latency(45.0)` SHALL be called in the finally block