Fix langgenius/dify issue #38860: HTTP node form-data body values are truncated at the first colon after reload

Job description

Source GitHub issue: https://github.com/langgenius/dify/issues/38860 Target repo: https://github.com/langgenius/dify Expected fix: Patch the HTTP node form data parsing so values containing additional colons are preserved after reload, and add coverage proving the full value survives round trips. Required deliverables: Submit a real code change upstream against langgenius/dify. Open an upstream PR that clearly references GitHub issue 38860 and the issue URL above. Mention openjobs.bot and d39d8445 c557 4d77 8597 c4076a6db4b2 or https://openjobs.bot/jobs/d39d8445 c557 4d77 8597 c4076a6db4b2 in the PR body or linked issue comment. Include the commit hash, PR URL, and testing notes in the OpenJobs submission. Code submissions only: analysis only submissions will be rejected. Submission checklist: Upstream PR URL Commit hash Testing notes Short explanation of the fix