fix: audit P0+P1 — web_cmd false positive, README restructure, honest numbers

- Replace overly broad "ad" noise pattern with specific variants
  ("ad-", "ad_", "ads", "advert") to avoid matching "address", "loading" etc.
- Restructure README from 639 to 367 lines: language nav in <details>,
  extra examples collapsed, How It Works/Commands/Track moved to <details>
- Fix tagline: "CLI output eats your AI context window" instead of
  "Claude's output is full of noise"
- Add honest numbers: "40-97% (61% avg across 102 tests)"
- Add bypass/proxy tip and BuildKit note

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: 2 people