ci: migrate CodeQL to advanced setup

[zeevdr]

Summary

• Disables CodeQL default-setup so the advanced workflow takes over
• Adds paths-ignore for the generated OpenAPI client (src/api/schema.d.ts) to avoid false positives on generated code
• Staggered weekly schedule (Monday 07:53 UTC) to avoid resource contention with other repos

Test plan

• Verify CodeQL advanced workflow appears under Actions after merge
• Confirm default-setup is no longer listed under repo Security settings
• Confirm generated OpenAPI client is excluded from analysis results

Closes #42
Closes #40

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