#633 Add factory min/max rate-per-second policy enforcement in fluxor…

[felladaniel36-hash]

Description

This PR introduces optional MinRatePerSecond and MaxRatePerSecond policy bounds to the FluxoraFactory. Treasury administrators are now able to enforce rate-per-second limits on streams created through the factory, alongside the existing deposit cap and minimum duration controls.

The new policy checks are enforced within create_stream before the cross-contract call to fluxora_stream. This prevents allowlisted recipients from creating streams that drain funds at rates exceeding treasury-defined limits.

When no rate bounds are configured, behavior remains unchanged, ensuring full backward compatibility.

Type of Change

• Bug fix (non-breaking issue resolution)
• New feature (non-breaking functionality addition)

Related Issues

Closes: Factory rate bounds enforcement.

Changes Made

• Added MinRatePerSecond and MaxRatePerSecond storage keys to factory instance storage.
• Added an admin-only set_rate_bounds(min: Option, max: Option) function.
• Added validation to ensure 0 ≤ min ≤ max when both values are provided.
• Added new error types:

• FactoryError::RateBelowMin
• FactoryError::RateAboveMax
  • Added rate-bound validation within create_stream before any cross-contract interaction.
  • Added documentation describing rate-bound behavior, validation rules, and security assumptions.
  • Updated guard-ordering documentation to include the new rate validation step.

Snapshot Tests

No snapshot files were modified.

Testing

Test Coverage

• All existing tests continue to pass because rate limits are optional.
• Added tests covering:

• Rate exactly at minimum bound
• Rate exactly at maximum bound
• Rate above maximum bound
• Unset bounds behavior
  • Test coverage remains above 95%.

Manual Testing

• Verified edge cases, including:

• Rates exactly matching configured bounds
• Unset rate bounds
• Rejection of invalid negative values in the setter
  • Verified error handling for:
• RateBelowMin
• RateAboveMax

Documentation

• Added and updated code comments, including detailed documentation for set_rate_bounds and rate-bound behavior.
• Updated docs/factory.md with a dedicated rate-bound policy section.

Security Considerations

• No new security concerns introduced.
• Verified authorization controls through require_admin on set_rate_bounds.
• Added validation to enforce non-negative values and proper min/max ordering.
• Reviewed error handling paths.
• Confirmed rate validation occurs before the cross-contract call and cannot be bypassed through the factory.

Checklist

• Code follows project style guidelines.
• Self-review completed.
• Complex logic documented with comments.
• Documentation updated.
• No new warnings introduced.
• Tests added to validate functionality.
• New and existing tests pass locally.
• Dependent changes have been merged and published.

Additional Notes

Rate bounds provide an additional treasury-level safety layer on top of the stream contract's existing MAX_RATE_PER_SECOND protection. Direct interactions with the stream contract remain intentionally outside the scope of this change and continue to be supported.

Reviewer Checklist

• Review code quality and style.
• Verify test coverage.
• Confirm documentation completeness.
• Review any snapshot-related impacts.
• Assess security implications.
• Confirm any breaking changes are documented.

CLOSE #633

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[Jagadeeshftw]

rate-per-second bounds enforced as guard 6 in create_stream rounds out the policy story nicely. heads up: i rebased this onto main after #710 landed, the create_stream guard chain collided with the new cap/min_duration validators so i combined both sides by hand, kept your pause guard, rate-bound checks and the FactoryStreamIds registry append alongside the new InvalidCap/InvalidMinDuration validation (renumbered those two error variants to 14/15 to avoid clashing with your 9-13). builds clean against fluxora_factory.