v0.4.0

Added

• Add code duplication gate (composer duplication:check) integrated into composer check to detect golden SQL/fixture ID duplicates, duplicate test names, and hotspot regressions.
• Add multiprocess SQLite write-contention probe (composer probe:sqlite:contention) testing concurrent WAL database transactions, SQLITE_BUSY surfacing, busy-timeout blocking, and 4-process write safety.
• Add memory-stability soak scenarios for streaming cursors and batch writes, per-sample allocation metrics, and a 256 KiB retained-allocation memory gate.
• Add hot-path benchmark scenarios (compile_allocation and terminal_reuse) and automated paired v0.3.0 baseline comparisons in CI.
• Record v0.3.0 baseline manifest, duplication/complexity inventory, performance/stability evidence, and ADR-015 for PHP 8.2+ attribute floor policy.

Changed

• Consolidate MySQL and MariaDB dialect compilers behind a shared @internal MySqlFamilyCompiler base.
• Unify clause condition construction into a single BuildsConditions dispatcher for where() and having().
• Centralize insert(), insertMany(), update(), and delete() write compilation and state validation in AbstractDialectCompiler.
• Extract connection lifecycle, DSN validation, and PDO options into @internal ConnectionProfile.
• Replace func_num_args() overload dispatch with explicit sentinel defaults (MISSING sentinel enum) and variadic catch-alls across clause methods, exposing reflection defaults while preserving exact where('col', null) behavior.
• Replace magic strings in AST internal state with closed enums (LockMode, LockModifier, JoinType).
• Reuse stateless dialect compilers and executors per Connection instance via @internal compilerForQueryBuilding() and executorForQueryBuilding() accessors, cutting compilation and terminal allocations.
• Shallow-clone condition and join state during query compilation snapshots (QueryState::copyForCompilation()), optimizing hot-path aggregate rewrites.
• Data-drive dialect golden assertions via JSON fixtures (tests/Fixtures/Compiler/*.json) and consolidate PDOStatement test doubles into ConfigurableStatement.
• Formalize PHP 8.2 runtime floor checks in composer check with check-platform-reqs, PHP linting, and PHPStan analysis floors.