[diskann-wide] Test unaligned loads properly.

[hildebrandmw]

Test under-aligned loads and stores in diskann-wide and documents that there are no alignment restrictions on the associated pointer.

This was supposed to be in #981 but somehow didn't make it into the diff.

[Copilot]

Pull request overview

This PR completes the diskann-wide portion of unaligned SIMD load/store support by documenting that pointer alignment is unrestricted and strengthening tests to exercise byte-level under-alignment.

Changes:

• Updates SIMDVector load/store documentation to remove scalar-alignment requirements.
• Reworks load/store test utilities to validate every byte offset, including predicated access paths.
• Adds bytemuck test support for safe byte-slice comparisons in test helpers.

Reviewed changes

Copilot reviewed 5 out of 6 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
diskann-wide/src/traits.rs	Documents no alignment requirements for SIMD load/store pointers.
diskann-wide/src/test_utils/common.rs	Adds byte-view helpers for test buffers.
diskann-wide/src/test_utils/load.rs	Tests full and predicated loads at byte-level offsets.
diskann-wide/src/test_utils/store.rs	Tests full and predicated stores at byte-level offsets.
diskann-wide/Cargo.toml	Adds dev dependencies/features needed for byte casting in tests.
Cargo.lock	Records the new diskann-wide dev dependency.

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[codecov-commenter]

Codecov Report

❌ Patch coverage is 86.23853% with 15 lines in your changes missing coverage. Please review.
✅ Project coverage is 89.45%. Comparing base (e2dc9a0) to head (61258d7).
⚠️ Report is 3 commits behind head on main.

Files with missing lines	Patch %	Lines
diskann-wide/src/test_utils/store.rs	80.95%	12 Missing ⚠️
diskann-wide/src/test_utils/load.rs	91.66%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1110      +/-   ##
==========================================
- Coverage   89.46%   89.45%   -0.02%     
==========================================
  Files         482      482              
  Lines       91082    91129      +47     
==========================================
+ Hits        81491    81523      +32     
- Misses       9591     9606      +15     

Flag	Coverage Δ
miri	89.45% <86.23%> (-0.02%)	⬇️
unittests	89.10% <86.23%> (-0.02%)	⬇️

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

Files with missing lines	Coverage Δ
diskann-wide/src/test_utils/common.rs	79.67% <100.00%> (+1.79%)	⬆️
diskann-wide/src/traits.rs	92.56% <ø> (ø)
diskann-wide/src/test_utils/load.rs	93.33% <91.66%> (-6.67%)	⬇️
diskann-wide/src/test_utils/store.rs	84.61% <80.95%> (-7.84%)	⬇️

... and 9 files with indirect coverage changes

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