Add Markstream installation skill 🤖🤖🤖

[Simon-He95]

Pull Request Checklist

• I have read and followed the CONTRIBUTING.md guidelines.
• I have read and followed the Guidance for submissions involving paid services.
• My contribution adds a new instruction, prompt, agent, skill, workflow, or canvas extension file in the correct directory.
• The file follows the required naming convention.
• The content is clearly structured and follows the example format.
• I have tested my instructions, prompt, agent, skill, workflow, or canvas extension with GitHub Copilot.
• I have run npm start and verified that README.md is up to date.
• I am targeting the main branch for this pull request.

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Description

Adds a focused markstream-install skill for GitHub Copilot users who need to select, install, and safely configure the appropriate Markstream package in an existing frontend project. It covers framework package selection, optional peers, CSS ordering, SSR boundaries, and streaming-renderer setup without requiring product sign-up links.

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Type of Contribution

• New instruction file.
• New prompt file.
• New agent file.
• New plugin.
• New skill file.
• New agentic workflow.
• New canvas extension.
• Update to existing instruction, prompt, agent, plugin, skill, workflow, or canvas extension.
• Other (please specify):

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Additional Notes

The source project is MIT-licensed and the contribution is maintained by its author. npm run skill:validate, npm run build, and git diff --check completed successfully. The GitHub Copilot interactive test and the template-specific npm start command have not been run.

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By submitting this pull request, I confirm that my contribution abides by the Code of Conduct and will be licensed under the MIT License.

[github-actions]

🔒 PR Risk Scan Results

Scanned 3 changed file(s).

Severity	Count
🔴 High	0
🟠 Medium	1
ℹ️ Info	0

Severity	Rule	File	Line	Match
🟠	package-exec-command	docs/README.skills.md	31	| [acreadiness-assess](../skills/acreadiness-assess/SKILL.md)<br />`gh skills install github/awesome-copilot acreadiness-assess` | Run the AgentRC readiness assessment on the curre

This is an automated soft-gate report. Findings indicate review targets and do not block merge by themselves.

[github-actions]

🔴 Contributor Reputation Check: HIGH risk

Check	Risk
Profile	HIGH
Credential audit	NONE

Maintainers: please review this contributor before merging.
See the workflow run for full details.
Automated check powered by AGT.

[github-actions]

🔍 Vally Lint Results

✅ All checks passed

Scope	Checked
Skills	1
Agents	0
Total	1

Severity	Count
❌ Errors	0
⚠️ Warnings	0
ℹ️ Advisories	0

Summary

Level	Finding
ℹ️	npm warn EBADENGINE Unsupported engine {
ℹ️	npm warn EBADENGINE package: 'commander@15.0.0',
ℹ️	npm warn EBADENGINE required: { node: '>=22.12.0' },
ℹ️	npm warn EBADENGINE current: { node: 'v20.20.2', npm: '10.8.2' }
ℹ️	npm warn EBADENGINE }
ℹ️	npm warn deprecated prebuild-install@7.1.3: No longer maintained. Please contact the author of the relevant native addon; alternatives are available.
ℹ️	✅ markstream-install (2/2 checks passed)
ℹ️	✓ [spec-compliance] All 1 skill(s) are spec-compliant.
ℹ️	✓ spec-compliance: All spec checks passed.
ℹ️	✓ [valid-refs] All file references across 1 skill(s) are valid.

Full linter output

### Linting skills/markstream-install
npm warn EBADENGINE Unsupported engine {
npm warn EBADENGINE   package: 'commander@15.0.0',
npm warn EBADENGINE   required: { node: '>=22.12.0' },
npm warn EBADENGINE   current: { node: 'v20.20.2', npm: '10.8.2' }
npm warn EBADENGINE }
npm warn deprecated prebuild-install@7.1.3: No longer maintained. Please contact the author of the relevant native addon; alternatives are available.
✅ markstream-install (2/2 checks passed)
    ✓ [spec-compliance] All 1 skill(s) are spec-compliant.
        ✓ spec-compliance: All spec checks passed.
    ✓ [valid-refs] All file references across 1 skill(s) are valid.
        ✓ valid-refs: All file references resolve to existing files within the skill directory.

1 skill(s) linted, 1 passed

[Copilot]

Pull request overview

Adds a Markstream installation skill covering framework selection, dependencies, styling, SSR, streaming, and security.

Changes:

• Adds the installation workflow and examples.
• Adds framework-specific scenario guidance.
• Registers the skill in generated documentation.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 5 comments.

File	Description
skills/markstream-install/SKILL.md	Defines the installation workflow.
skills/markstream-install/references/scenarios.md	Maps frameworks, peers, CSS, and input modes.
docs/README.skills.md	Adds the skill to the catalog.

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated no new comments.

[Copilot]

Review details

• Files reviewed: 3/3 changed files
• Comments generated: 2
• Review effort level: Medium

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

Comments suppressed due to low confidence (1)

skills/markstream-install/references/scenarios.md:42

• The input matrix also omits the documented Vue 2 exception: high-frequency SSE, long conversations, and large code/table/math blocks should use externally parsed nodes to avoid reparsing the entire content value for every token. Without that case, this mandatory reference can select the expensive input path for the Vue 2 package.

- `nodes` plus `final`: worker-preparsed content, shared AST stores, custom AST transforms, or cases where another layer already owns parsing.