chore(deps): update rust crate tower to v0.5.3

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
tower	workspace.dependencies	patch	0.5.2 → 0.5.3

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Release Notes

tower-rs/tower (tower)

v0.5.3: tower 0.5.3

Compare Source

Added

• builder: Add ServiceBuilder::boxed_clone_sync() helper (#​804)

Fixed

• retry: Check that supplied jitter is not NaN (#​843)

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Configuration

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[claude]

PR Review: Update tower from 0.5.2 to 0.5.3

Summary

This is a minor patch update from Renovate that updates the tower crate from version 0.5.2 to 0.5.3. The change is safe to merge.

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Code Quality ✅

• Change scope: Minimal - only updates Cargo.lock with new version and checksum
• Conventional commits: Follows project standards with chore(deps): prefix
• Automated maintenance: Proper use of Renovate for dependency updates

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Potential Issues ✅ None Found

After reviewing the codebase:

1. Tower usage is minimal and safe:

   • Only used for basic Layer and Service traits in scotty/src/api/rate_limiting/middleware.rs
   • Project only uses tower with util feature: tower = { version = "0.5", features = ["util"] }
   • No usage of the features affected by this patch (retry with jitter, ServiceBuilder boxed_clone_sync)

2. Retry logic is custom:

   • Project implements its own retry mechanism in scotty-core/src/http/retry.rs
   • Does NOT use tower's retry functionality (which had the jitter NaN fix)

3. Service builder not used:

   • No usage of ServiceBuilder in the codebase
   • The new boxed_clone_sync() helper is irrelevant

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Performance Considerations ✅

• Patch version bump - no performance impact expected
• Tower v0.5.3 fixes:
  • Added ServiceBuilder::boxed_clone_sync() helper (#804)
  • Fixed retry jitter NaN validation (#843)

Neither of these changes affects the current usage patterns in Scotty.

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Security Concerns ✅

• No security-related changes in this patch
• Standard dependency update from a trusted crate (tower-rs)
• Checksum update is expected and correct

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Test Coverage ✅

• This is a patch-level dependency update
• Existing tests should provide adequate coverage
• CI checks will validate compatibility (if enabled)

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Recommendation

✅ APPROVE & MERGE - This is a safe, routine dependency update with no breaking changes or compatibility concerns for the Scotty project.