chore: release omp-telegram 0.13.0

[TerrifiedBug]

Bumps the package and guide example to 0.13.0.

Includes the two merged features:

• feat: add optional Telegram rich Markdown output #80: optional rich Markdown output, with MarkdownV2 still the default. The maintainer tested it locally. Closes Support Telegram Rich Markdown / sendRichMessage for outbound formatting #79.
• Announce provider failures to the active Telegram chat #78: provider failure, retry, and recovery notices. Follow-up fixes preserve routing and prompt tools across continuations and prevent stale errors from being reported on healthy runs. Closes Run failures (provider errors, e.g. quota exhausted / 429) are silently swallowed — nothing reaches the Telegram topic #77.

Requires omp 18.1.16 or newer for the continuation lifecycle contract.

Validation: Bun 1.3.14 typecheck and all 380 tests pass. npm pack --dry-run succeeds. After merging, tag v0.13.0 to trigger the existing npm trusted-publishing workflow.