v0.3.4

Documentation patch — sync README.md + README.en.md to reflect
features shipped in 0.2.0 / 0.2.1 / 0.3.0 / 0.3.1 / 0.3.2 that were
documented in CHANGELOG but never propagated to README. PyPI's package
page renders README, so three releases of new functionality were
invisible to anyone landing on https://pypi.org/project/a11y-moda/ —
they would still see the pre-0.2.0 "scan / site only" framing.

No code change. PyPI wheel is bit-for-bit equivalent to 0.3.3 except
for the README rendered on the package page.

Changed (docs)

• README.md — restructured around the three-layer mental model
  (lint write-time / rules knowledge service / scan runtime).
  Adds dedicated sections for each command. Adds "lint vs scan"
  decision table. Splits install into standard (~30MB) and [scan]
  extra (~290MB) with the v0.3.0 BREAKING change called out at the
  top of Install. Verbose flag tables and the AAA mechanism breakdown
  collapsed into <details> so above-the-fold stays scannable. TOC
  added.
• README.en.md — mirror of the zh-TW restructure. Same sections
  in English, no <details> collapse (English README is shorter
  overall and serves as a pointer to the zh-TW for full detail).
• Tagline — both READMEs updated from "scan / site CLI" framing
  to "lint + scan + rule lookup" to match the v0.3.0 knowledge-service
  reframing.

Notes

• Why this took until 0.3.4 — diagnosed during a PyPI page review.
  Root cause: no release SOP enforced README sync alongside CHANGELOG
  bumps. Fixed in freego_cli/CLAUDE.md (parent monorepo doc) under
  the new "發版檢查清單 (release SOP)" section, and in this project's
  contributor memory as feedback_release_readme_sync.
• Why a patch (not minor) — the underlying CLI surface, rule set,
  and behaviour are unchanged from 0.3.3. Only the rendered package
  page on PyPI changes. SemVer-wise this is the smallest version bump
  that triggers a PyPI republish.