chore: release v0.13.0

[tempo-github-sts]

This PR was opened by the Changelogs release workflow.

When you're ready to release, merge this PR and the packages will be published.

---

0.13.0 (2026-09-30)

Minor Changes

• Add ordered currencies configuration to the Tempo method. Servers now accept OUSD then USDC.e on Tempo mainnet and OUSD then pathUSD on Moderato by default, issuing one charge Challenge per accepted currency in order; other chains keep their single default currency. An explicit currencies list replaces the defaults, and the singular currency option, now deprecated for servers, still restricts acceptance to that one currency. Per-request currency overrides still issue a single Challenge. Local fee payers no longer pay gas in the charge currency: they use the new fee_token option, or else the first token in allowed_fee_tokens (default: fee_tokens_for_chain(), pathUSD then USDC.e on mainnet) that covers the transaction gas budget, falling back to the first allowed token, so sponsored OUSD charges pay fees in pathUSD or USDC.e. A configured fee token outside the allowed list is rejected. Hosted fee payer URLs are unchanged. Add the OUSD constant and default_currencies_for_chain(). default_currency_for_chain(), fee tokens, and fee payer policies are unchanged, and Stripe's Tempo rail keeps its single USDC.e or pathUSD currency.
• Unsponsored OUSD charges select a funded supported gas token independently of the payment currency. Sponsor token selection skips insufficient dust balances and rounds the maximum gas budget up to microdollars.
• Update the PyJWT pin to 2.15.1 in the Tempo, Stripe, and MCP extras to include upstream security fixes. (by @DerekCofausper, #265)