Implement SQLite WAL mode and performance optimizations

[anitnilay20]

Description

Add WAL (Write-Ahead Logging) mode support and various SQLite performance optimizations.

Requirements

• WAL mode configuration
• PRAGMA optimizations
• Connection pooling for SQLite
• Prepared statement caching
• Vacuum and maintenance operations
• Write comprehensive tests

Acceptance Criteria

• WAL mode support with configuration
• Automatic PRAGMA optimizations
• Efficient connection reuse
• Maintenance operation support

Files to modify

• beatrix_core/src/relational/db/sqlite.rs
• beatrix_core/src/relational/pool.rs

Example Usage

let db = SQLite::new("database.db")
    .wal_mode(true)
    .cache_size(64 * 1024) // 64MB cache
    .optimize_for_writes()
    .connect().await?;

// Periodic maintenance
db.vacuum().await?;
db.analyze().await?;