fix(channel): render inline HTML in Telegram list items

[codeaholicguy]

Summary

• Markdown lists with inline markup (bold/code/italic) rendered tags literally in Telegram: the list renderer block-parsed item tokens, and marked's synthetic paragraph text token re-escaped the already-rendered HTML.
• Fix: render list-item text tokens inline exactly once via parser.parseInline(token.tokens!), block-parse non-text tokens (paragraphs, nested lists); drop the now-unreachable custom listitem() and the dead text() nested-token branch; escape inline raw HTML while stripping block HTML.

Validation

• channel-connector: 112/112 tests; coverage 75.15% branches global (threshold 75), telegramHtml.ts 97.72% stmts / 87.5% branches
• typecheck + build + repo-wide lint: exit 0 (pre-existing warnings only)
• Mutation check: reverting the fix fails 8 regression cases (tight/loose ordered+unordered lists, links, literal <script> escaping)
• Full workspace pre-commit suite green after npm ci + npm run build