fix(workflows:review): fix formatting issues causing broken rendering

[XSAM]

Summary

• Fixed "Next Steps" items 3 & 4 and Severity Breakdown that leaked outside the Summary Report markdown template
• Fixed section numbering jumping from 5 to 7 (renumbered to 6)
• Removed two orphaned fenced code block delimiters that caused the entire End-to-End Testing section to render as a code block
• Fixed unclosed quoted string in section 1 task list