Pin Server rc.69 to Workflow rc.55

[rmcdaniel]

Closes #62.

• pins the installable Workflow 2.0.0-rc.55 package and exact source commit;
• advances Server source, image, Compose, and Helm metadata to 2.0.0-rc.69;
• advances the Helm chart to 0.1.65; and
• aligns affected resume-sequence fixtures with the current protocol contract.

Focused validation:

• 3 PHPUnit tests, 169 assertions
• Composer lock validation (the expected exact-prerelease-constraint warning remains)
• git diff --check

Stable publication is not part of this PR.