Draft: using PersistenceLayer in pvm storage

[thomasathorne]

Closes TZX-72

What

This PR adds the persistence layer to the PVM storage without changing the chunking logic at all.

After implementing, we decided this is not an improvement and it would be better to restructure the PVM storage before switching to using the persistence layer. This branch is useful for testing though, so I've created this PR as a draft.

Why

We will switch to the persistence layer at some point, though it won't look exactly like this.

How

This branch takes the path of least refactoring, so the chunked_io module is left basically untouched. The Store is turned into a wrapper around the persistence layer and the Repo is turned into a wrapper around DirectoryManager.

Manually Testing

make all

Tasks for the Author

• Link all Linear issues related to this MR using magic words (e.g. part of, relates to, closes).
• Eliminate dead code and other spurious artefacts introduced in your changes.
• Document new public functions, methods and types.
• Make sure the documentation for updated functions, methods, and types is correct.
• Add tests for bugs that have been fixed.
• Explain changes to regression test captures when applicable.
• Write commit messages in agreement with our guidelines.
• Self-review your changes to ensure they are high-quality.
• Complete all of the above before assigning this MR to reviewers.

[codecov]

Codecov Report

❌ Patch coverage is 57.81250% with 27 lines in your changes missing coverage. Please review.
✅ Project coverage is 91.07%. Comparing base (a200200) to head (996a2d4).
⚠️ Report is 6 commits behind head on main.

Files with missing lines	Patch %	Lines
src/riscv/lib/src/storage.rs	57.14%	4 Missing and 23 partials ⚠️

❌ Your patch check has failed because the patch coverage (57.81%) is below the target coverage (80.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #838      +/-   ##
==========================================
- Coverage   91.14%   91.07%   -0.07%     
==========================================
  Files         111      112       +1     
  Lines       21288    21258      -30     
  Branches    21288    21258      -30     
==========================================
- Hits        19402    19360      -42     
+ Misses       1508     1507       -1     
- Partials      378      391      +13     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.