Add security warning for accounts with inline keys

[chasefleming]

Description

Adds a security warning when running CLI commands if accounts have inline keys stored directly in flow.json.

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For contributor use:

• Targeted PR against master branch
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work
• Code follows the standards mentioned here
• Updated relevant documentation
• Re-reviewed Files changed in the Github PR explorer
• Added appropriate labels

[github-actions]

Dependency Review

✅ No vulnerabilities or license issues or OpenSSF Scorecard issues found.

Scanned Files

None

[codecov-commenter]

Codecov Report

❌ Patch coverage is 0% with 19 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
internal/command/command.go	0.00%	19 Missing ⚠️

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