Add agentic workflow to auto-bump TCGC for http-client-csharp

[Copilot]

Adds a daily GitHub Agentic Workflow that checks for new stable releases of @azure-tools/typespec-client-generator-core and opens a PR to upgrade http-client-csharp when one is found.

• Trigger: schedule: daily with workflow_dispatch for manual runs — checks npm for the latest non-dev TCGC version
• Duplicate PR detection: Searches for any existing open PR targeting the same TCGC version with the emitter:client:csharp label before proceeding; exits without creating a new PR if one already exists
• No-op when current: Compares against devDependencies in packages/http-client-csharp/package.json; exits without creating a PR if already up to date
• Upgrade delegation: Reads and follows the step-by-step migration instructions defined in .github/prompts/upgrade-tcgc.instructions.md, which handles dependency synchronization, peer resolution, build validation, and test regeneration
• Safe outputs: Restricted to create-pull-request only with draft: true, protected-files: fallback-to-issue; read-all permissions; no explicit labels (repo applies them automatically)
• Frontmatter format: Follows the canonical format from githubnext/agentics samples — includes name, description, network, timeout-minutes, edit:, and bash: true
• Lock file: Includes the compiled bump-tcgc-csharp.lock.yml generated by gh aw compile, along with a .gitattributes entry marking *.lock.yml as linguist-generated=true merge=ours

This replaces the manual process of filing an issue + assigning Copilot for each TCGC patch/minor bump (e.g. commits 458f881, f3bdd60).

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Create an Agentic Workflow to Automatically Upgrade TCGC Dependency for the http-client-csharp package</issue_title>
<issue_description>We should look into creating a new agentic workflow that automates the version bump process for tcgc. The workflow should run once a day and check if a new non-dev tcgc version is available at https://www.npmjs.com/package/@azure-tools/typespec-client-generator-core and if that version is newer than the one used in http-client-csharp. If there is no new version, no PR should be opened. If there is a new version, then a PR should be opened with the code updates. Some examples of this being done previously:

• 458f881
• f3bdd60</issue_description>

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

• Fixes Create an Agentic Workflow to Automatically Upgrade TCGC Dependency for the http-client-csharp package #10013

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[jorgerangel-msft]

@copilot we are missing the lock file https://github.github.com/gh-aw/reference/faq/#what-is-a-workflow-lock-file

[jorgerangel-msft]

@copilot address the feedback

[Copilot]

Added the compiled lock file in 03d9e23 by running gh aw compile. This also added a .gitattributes entry to mark *.lock.yml files as linguist-generated=true merge=ours.

[jorgerangel-msft]

@copilot what does the gitattributes addition do?

[Copilot]

The .gitattributes entry .github/workflows/*.lock.yml linguist-generated=true merge=ours was added automatically by gh aw compile. It does two things:

1. linguist-generated=true — tells GitHub's Linguist that lock files are machine-generated, so they won't count toward language statistics and will be collapsed by default in PR diffs.
2. merge=ours — during git merges, always keeps "our" version of the lock file to prevent merge conflicts on the auto-generated content.

This entry was added by the gh aw compile tool itself, not manually.

[Copilot]

Just as a heads up, I was blocked by some firewall rules while working on your feedback. Expand below for details.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• github.github.com
  • Triggering command: /home/REDACTED/work/_temp/ghcca-node/node/bin/node /home/REDACTED/work/_temp/ghcca-node/node/bin/node --enable-source-maps /home/REDACTED/work/_temp/copilot-developer-action-main/dist/index.js (dns block)
• github.github.io
  • Triggering command: /home/REDACTED/work/_temp/ghcca-node/node/bin/node /home/REDACTED/work/_temp/ghcca-node/node/bin/node --enable-source-maps /home/REDACTED/work/_temp/copilot-developer-action-main/dist/index.js (dns block)
• https://api.github.com/graphql
  • Triggering command: /usr/bin/gh gh auth status (http block)
• https://api.github.com/repos/actions/github-script/git/ref/tags/v8
  • Triggering command: /usr/bin/gh gh api /repos/actions/github-script/git/ref/tags/v8 --jq .object.sha (http block)
• https://api.github.com/repos/github/gh-aw/git/ref/tags/v0.57.2
  • Triggering command: /usr/bin/gh gh api /repos/github/gh-aw/git/ref/tags/v0.57.2 --jq .object.sha (http block)
• https://api.github.com/repos/github/gh-aw/releases/latest
  • Triggering command: /usr/bin/gh gh extension install github/gh-aw (http block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

[timotheeguerin]

@jorgerangel-msft before you spend too much time on this, currently github actions in microsoft repos are not allowed to create PRs, see Timo's post in the ai discussion

[jorgerangel-msft]

@timotheeguerin thanks for the heads up, I wasn't aware. I'll table this for now