test(website): extend the public-copy gate to rendered component copy

The unit gate read `apps/website/content/**` only, so every word a component
renders and every line of the published package READMEs was invisible to it.
Both gaps have already shipped violations: the homepage FAQ asserted
"Installation is inert" and linked `/docs/telemetry/guides/browser`, and
`libs/telemetry/README.md` carried three barred claims live on npm.

`src/**` is scanned through the TypeScript parser rather than as bytes, so only
string literals, static template chunks and JSX text are compared. Comments and
regex literals — which is how this repository legitimately discusses the barred
phrases — are skipped by construction, not by an ignore list, which keeps the
exclusions down to the contract module and `*.spec.*`. The READMEs are prose and
get the same plain line scan `content/**` gets.

Fixtures reconstruct the shipped FAQ answer so the gate stays provably
non-vacuous, and the spec states what it catches and what only the e2e crawl
can. Adds ~1s to the suite.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

Author: blove