/**
* htmlLoader — HTML with the tags taken out, without a parser.
*
* Pattern: Adapter behind `DocumentLoader`.
* Role: rag/ layer. Zero dependency.
* Emits: N/A.
*
* ── What this is, and what it is not ────────────────────────────────────────
* This is a **tag stripper**, not an HTML parser, and the distinction is worth
* being blunt about because the failure mode is silent. It removes `