Refactor for clippy and speed

.gitignore

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 .idea/
 target/
+.DS_Store
+dhat-heap.json
+profile.json
+profile.json.gz

AGENTS.md

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+# CLAUDE.md
+
+## Project overview
+
+pgweasel is a fast CLI PostgreSQL log parser written in Rust (edition 2024, MSRV 1.92). It aggregates errors, locks, slow queries, connections, and system events from Postgres log files.
+
+## Build & test commands
+
+```bash
+cargo build            # Build
+cargo test             # Run all tests (unit + integration)
+cargo test --test connections  # Run a single integration test file
+cargo clippy --all-targets -- -W clippy::pedantic  # Lint (always run in pedantic mode)
+cargo fmt --all -- --check # Check formatting
+```
+
+Each change should check tests and formatting, and if necessary fix.
+Also each change should write app tests using new functionality.
+
+## Commiting changes
+
+Usually changes are done according to GitHub issues which are stated in subject:
+
+`#12 Added sorting for connections analysis`
+
+## Project structure
+
+- `src/main.rs` — CLI entry point (clap-based subcommands: `err`, `locks`, `slow`, `conn`, `system`)
+- `src/aggregators/` — One aggregator per feature (connections, error_frequency, error_histogram, top_slow_query)
+- `src/filters/` — Log line filters
+- `src/format/` — Log format detection and parsing
+- `src/output_results/` — Output orchestration
+- `tests/` — Integration tests using `assert_cmd` + `predicates`, one file per subcommand
+- `tests/files/` — Sample log files for tests
+
+## Conventions
+
+- Integration tests run the compiled binary via `assert_cmd::cargo::cargo_bin!("pgweasel")` and assert on stdout/stderr
+- Aggregators implement the `Aggregator` trait (`update`, `merge_box`, `print`, `boxed_clone`, `as_any`)
+- Sorted output sections use `Vec::sort_by` on collected HashMap entries, sorted descending by count
+- Use `memchr::memmem` for fast byte-level string searches in hot paths
+- Parallel processing via `rayon`; aggregator results merged with `merge_box()`

CLAUDE.md

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+AGENTS.md