docs: use REST API endpoint for C8run deployment instructions

[Copilot]

Description

Updated C8run documentation to default to REST API endpoint (http://localhost:8080) instead of gRPC endpoint (http://localhost:26500) for deployment and interaction instructions, while keeping gRPC endpoint documented for reference.

Changes:

• Desktop Modeler deployment instructions now use http://localhost:8080 (C8run) and http://localhost:8088 (Docker Compose)
• gRPC endpoint (http://localhost:26500) remains documented in available endpoints and APIs sections

Files modified:

• Getting started guides (example and human tasks)
• C8run quickstart documentation
• Docker Compose deployment instructions
• Versioned docs (8.8)

When should this change go live?

• [ ] This is a bug fix, security concern, or something that needs urgent release support. (add bug or support label)
• [ ] This is already available but undocumented and should be released within a week. (add available & undocumented label)
• [ ] This is on a specific schedule and the assignee will coordinate a release with the Documentation team. (create draft PR and/or add hold label)
• [ ] This is part of a scheduled alpha or minor. (add alpha or minor label)
• [x] There is no urgency with this change (add low prio label)

PR Checklist

• [x] The commit history of this PR is cleaned up, using {type}(scope): {description} commit message(s)

• [x] My changes are for an upcoming minor release and are in the /docs directory (version 8.9).

• [x] My changes are for an already released minor and are in a /versioned_docs directory.

• [x] I added a DRI, team, or delegate as a reviewer for technical accuracy and grammar/style:

  • [x] Engineering team review
  • [x] Technical writer review via @camunda/tech-writers unless working with an embedded writer.

Original prompt

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This section details on the original issue you should resolve

<issue_title>Use REST API endpoint for C8run in every documentation</issue_title> <issue_description>As we have defaulted everything to REST, we should modify all documentation pointing to c8run deployment and interactions to use the REST endpoint instead of the gRPC one.

Context can be found in this slack thread: https://camunda.slack.com/archives/C050G7VJWJV/p1768207188659049</issue_description>

<agent_instructions>The one we want everywhere to use: Orchestration Cluster REST API: http://localhost:8080/ The one we want to get rid and not to use: Zeebe API (gRPC): http://localhost:26500/ </agent_instructions>

Comments on the Issue (you are @copilot in this section)

• Fixes camunda/camunda-docs#7705

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[bojtospeter]

@copilot don't change the package-lock.json file in your PR

[Copilot]

@copilot don't change the package-lock.json file in your PR

Done. Reverted the package-lock.json changes in commit 01dce82. The PR now only includes documentation changes.

[mesellings]

@zaycodes can you take a look at this one please? 🙏

[github-actions[bot]]

:wave: :robot: :thinking: Hello, @bojtospeter! Did you make your changes in all the right places?

These files were changed only in versioned_docs/version-8.8/. You might want to duplicate these changes in docs/.

• versioned_docs/version-8.8/self-managed/quickstart/developer-quickstart/c8run.md

You may have done this intentionally, but we wanted to point it out in case you didn't. You can read more about the versioning within our docs in our documentation guidelines.

[bojtospeter]

The unversionedc8run.md does not contain any information about usage (due to Operate not working with H2). So it's intentional not to have it in the PR right now.