feat: collect extract stats

[Crauzer]

No description provided.

[Copilot]

Pull request overview

Adds extraction summary statistics to wadtools extract, including counts, total bytes written, and a per-file-type breakdown.

Changes:

• Introduces ExtractStats returned from Extractor::extract_chunks, tracking extracted/skipped counts, total bytes written, and counts by LeagueFileKind.
• Adds an extract CLI flag to show stats and prints a formatted summary after extraction.
• Moves format_size into utils for reuse and adds dashmap as a dependency to aggregate per-type counts concurrently.

Reviewed changes

Copilot reviewed 6 out of 7 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
crates/wadtools/src/utils/mod.rs	Adds shared format_size() helper used by list/extract output.
crates/wadtools/src/main.rs	Adds --stats/-s option to the extract subcommand and wires it into ExtractArgs.
crates/wadtools/src/extractor.rs	Implements ExtractStats collection (bytes + per-type counts) during extraction.
crates/wadtools/src/commands/list.rs	Switches to shared utils::format_size (removes local copy).
crates/wadtools/src/commands/extract.rs	Prints extraction summary stats (including bytes and by-type breakdown).
crates/wadtools/Cargo.toml	Adds dashmap dependency.
Cargo.lock	Locks dashmap and transitive dependencies.

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