Add 3.7.0-rc1 release notes

[Copilot]

Purpose

Add developer-facing changelog documentation for Elsa 3.7.0-rc1.

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Scope

Select one primary concern:

• Bug fix (behavior change)
• Refactor (no behavior change)
• Documentation update
• Formatting / code cleanup
• Dependency / build update
• New feature

If this PR includes multiple unrelated concerns, please split it before requesting review.

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Description

Problem

The 3.7.0-rc1 release did not have a repository changelog entry under doc/changelogs.

Solution

• Release notes

  • Added doc/changelogs/3.7.0-rc1.md.
  • Used comparison range 3.7.0-preview1...3.7.0-rc1.
  • Summarized developer-impacting changes across modular server runtime, shell feature registration, HTTP JavaScript feature dependencies, expression type formatting fixes, CI, and tests.

• Traceability

  • Included short commit links and PR links where available.
  • Kept the required “Full changelog (short)” section for all range items.

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Verification

Steps:

1. Review doc/changelogs/3.7.0-rc1.md.
2. Confirm the comparison range and linked commits match 3.7.0-preview1...3.7.0-rc1.
3. Confirm sections omit empty categories and focus on developer-facing impact.

Expected outcome:

The changelog accurately summarizes the 3.7.0-rc1 release and follows the existing doc/changelogs format.

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Screenshots / Recordings (if applicable)

N/A

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Commit Convention

We recommend using conventional commit prefixes:

• fix: – Bug fixes (behavior change)
• feat: – New features
• refactor: – Code changes without behavior change
• docs: – Documentation updates
• chore: – Maintenance, tooling, or dependency updates
• test: – Test additions or modifications

Clear commit messages make reviews easier and history more meaningful.

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Checklist

• The PR is focused on a single concern
• Commit messages follow the recommended convention
• Tests added or updated (if applicable)
• Documentation updated (if applicable)
• No unrelated cleanup included
• All tests pass