// Strips HTML/XHTML to a plain text + ESC-token string suitable for rendering.
//
// Output format:
// - Every paragraph begins with an alignment token: ESC + 'L'|'C'|'R'
// - Paragraphs are separated by '\n\n'
// - Single '\n' = line break within a paragraph
// - Bold/italic spans are bracketed by ESC tokens (for future span rendering):
// ESC+'B' = bold on, ESC+'b' = bold off
// ESC+'I' = italic on, ESC+'i' = italic off
// - All inline ESC tokens are 2 bytes (ESC + code); renderers that don't
// support inline styles strip them before setting label text.
//
// HTML handling:
// - / → center aligned; - → left aligned
// -
,
with style="text-align: center/right" → center/right aligned
// - , , → bold on/off tokens
// - , , → italic on/off tokens
// -
→ '\n'
// - → '\n- ' prefix
// -