Added Jira integration with two new commands. jira auth handles authentication via API token, prompting for site, email, and token then persisting the site and email to ~/.assist/jira.json for future use. jira ac fetches and prints acceptance criteria for a given issue key, converting Atlassian Document Format to readable markdown text with support for headings, ordered and bullet lists, and inline code.

Also fixed gh api calls in the PR comment resolution flow to suppress JSON output that was being dumped to the terminal by piping stdout to pipe instead of inherit.