Remove unnecessary distance function implementations.

[hildebrandmw]

Remove unnecessary distance function implementations. These are no longer needed now that distance computations are plumbed through ElementRef instead of Element directly.

[Copilot]

Pull request overview

This PR removes now-redundant DistanceFunction overload impls (previously used to smooth over extra reference layers / Vec<u8> wrappers) after distance computations were moved to flow through ElementRef rather than Element.

Changes:

• Removed several DistanceFunction impls for DistanceComputer that accepted &&[u8] / &Vec<u8> wrappers.
• Removed DistanceFunction / PreprocessedDistanceFunction impls that adapted arc_swap::Guard<Arc<Vec<u8>>> to slices in the in-memory quant provider.
• Updated affected tests to pass &[u8] (via .as_slice() / deref) and adjusted trait imports accordingly.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
diskann-providers/src/model/pq/distance/dynamic.rs	Drops wrapper DistanceFunction impls for DistanceComputer (keeping the core slice-based impls).
diskann-providers/src/model/graph/provider/async_/memory_quant_vector_provider.rs	Removes Guard-based distance trait impls; updates tests/imports to use slice-based calls.
diskann-providers/src/model/graph/provider/async_/fast_memory_quant_vector_provider.rs	Updates tests to pass &[u8] directly instead of &&[u8].
diskann-providers/src/model/graph/provider/async_/bf_tree/quant_vector_provider.rs	Updates tests to pass &[u8] (via .as_slice()) for quant distance comparisons.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.50%. Comparing base (45428af) to head (124dcd6).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1008   +/-   ##
=======================================
  Coverage   89.49%   89.50%           
=======================================
  Files         448      448           
  Lines       84118    84090   -28     
=======================================
- Hits        75282    75263   -19     
+ Misses       8836     8827    -9     

Flag	Coverage Δ
miri	89.50% <100.00%> (+<0.01%)	⬆️
unittests	89.34% <100.00%> (+<0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
...ovider/async_/fast_memory_quant_vector_provider.rs	98.46% <100.00%> (ø)
...ph/provider/async_/memory_quant_vector_provider.rs	98.26% <100.00%> (-0.10%)	⬇️
diskann-providers/src/model/pq/distance/dynamic.rs	91.30% <ø> (+4.38%)	⬆️

... and 1 file with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.