Skip strings already wrapped in `t()` or `<Trans>`

[idomy]

Problem

On a partly-internationalized app, extract re-grabs text that is already inside a t("...") call or a <Trans> element. Those should not be extracted again.

Proposal

In the extractor, skip:

• string literals that are arguments to t(...) / i18n.t(...)
• JSX text inside <Trans>...</Trans>

Acceptance criteria

• A fixture containing both t("Hello") and a bare <p>Hello</p> extracts only the bare one.
• The existing demo fixture still extracts 11 strings (no regressions).

Pointers

• src/extract.mjs -> renderContext() and the StringLiteral / JSXText visitors.
• Add the new fixture under examples/.