feat(cli): `statsJson`, `progress`, `verbose` flags

[lukekania]

Goal

Implement the three observability options that today are no-ops in ngc-rs.

Current state

• statsJson: true — silently ignored. Angular emits stats.json for webpack-bundle-analyzer compatibility.
• progress: true — silently ignored.
• verbose: true — silently ignored. Today users have to set RUST_LOG=info.

Scope

• statsJson: emit a dist/stats.json with chunk graph + per-module sizes in webpack-stats schema (compatible with webpack-bundle-analyzer and similar tools). Bundler already has the data via ngc_bundler::ChunkGraph.
• progress: emit a tracing-subscriber-driven progress bar to stderr in TTY mode. Skip in non-TTY (CI).
• verbose: equivalent to RUST_LOG=info — adjust the tracing-subscriber filter at runtime when set.

Definition of done

• statsJson: true emits a stats.json consumable by webpack-bundle-analyzer.
• progress: true shows a per-stage progress bar in interactive shells.
• verbose: true matches RUST_LOG=info output without requiring the env var.