refactor(router): enforce instance identity positively instead of str…

[burhan-wesolves]

…ipping input

The previous fix conditionally ran the subtractive sanitizeUntrustedInput based on whether a URL param happened to be present. That inferred a route's scope indirectly and still relied on blanket field-stripping.

Replace it with a positive invariant: capture the guard-authenticated :instanceName from the URL up front, then after hydrating the DTO from query/body, force that value back onto the DTO + schema ref and drop any instanceId supplied via query/body. The URL identity is thus the single source of truth on scoped routes — a caller can never redirect the request to another instance (cross-instance auth bypass, CVE-2435 / evolution-foundation#2549) — while param-less listing routes (GET /instance/fetchInstances?instanceId=…) keep their query filters, so the manager opens the instance it was asked for.

Verified: fetchInstances?instanceId=X returns exactly X; a scoped route with a conflicting ?instanceName= override still operates on the URL instance.

📋 Description

🔗 Related Issue

Closes #(issue_number)

🧪 Type of Change

• [ * ] 🐛 Bug fix (non-breaking change which fixes an issue)
• ✨ New feature (non-breaking change which adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to not work as expected)
• 📚 Documentation update
• 🔧 Refactoring (no functional changes)
• ⚡ Performance improvement
• 🧹 Code cleanup
• 🔒 Security fix

🧪 Testing

• Manual testing completed
• Functionality verified in development environment
• No breaking changes introduced
• Tested with different connection types (if applicable)

📸 Screenshots (if applicable)

✅ Checklist

• My code follows the project's style guidelines
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have manually tested my changes thoroughly
• I have verified the changes work with different scenarios
• Any dependent changes have been merged and published

📝 Additional Notes