chore: Update gem-team plugin version to 1.84.0 and refine concurrency language in agent execution steps

[mubaidr]

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

chore: Update gem-team plugin version to 1.84.0 and refine concurrency language in agent execution steps

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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

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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 18 changed file(s).

Severity	Count
🔴 High	0
🟠 Medium	3
ℹ️ Info	0

Severity	Rule	File	Line	Match
🟠	package-exec-command	agents/gem-implementer-mobile.agent.md	52	- Metro: Error → `npx expo start --clear`.
🟠	package-exec-command	agents/gem-implementer-mobile.agent.md	55	- Native module: Missing → `npx expo install`.
🟠	package-exec-command	agents/gem-mobile-tester.agent.md	73	- Metro → `npx react-native start --reset-cache`.

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

[github-actions]

🔍 Vally Lint Results

⚠️ Warnings or advisories found

Scope	Checked
Skills	0
Agents	16
Total	16

Severity	Count
❌ Errors	0
⚠️ Warnings	0
ℹ️ Advisories	1

Summary

Level	Finding
ℹ️	Vally currently lints SKILL.md content. Agent files were detected but skipped:

Full linter output

### Agent files detected (not linted by vally)
ℹ️ Vally currently lints SKILL.md content. Agent files were detected but skipped:
agents/gem-browser-tester.agent.md
agents/gem-code-simplifier.agent.md
agents/gem-critic.agent.md
agents/gem-debugger.agent.md
agents/gem-designer-mobile.agent.md
agents/gem-designer.agent.md
agents/gem-devops.agent.md
agents/gem-documentation-writer.agent.md
agents/gem-implementer-mobile.agent.md
agents/gem-implementer.agent.md
agents/gem-mobile-tester.agent.md
agents/gem-orchestrator.agent.md
agents/gem-planner.agent.md
agents/gem-researcher.agent.md
agents/gem-reviewer.agent.md
agents/gem-skill-creator.agent.md