Expose counter to support more efficient sync

[dereknance]

🎟️ Tracking

PM-22201

📔 Objective

Mobile clients need to know if the FIDO 2 counter property is nonzero in order to determine if sync is required before performing authentication.

Updates cargo-udeps in lint.yml to version 0.1.57. Previous version was 9 months old. Locally, I was experiencing a bug where cargo-udeps was considering #[cfg(test)] to be invalid.

Updates a couple static assertions that were showing up as unused when running cargo +nightly udeps --workspace --all-features locally. Unsure why this wasn't previously showing up in CI.

Added an explicit lifetime to fix a mismatched-lifetime-syntax error, again when running the udeps check locally.

⏰ Reminders before review

• Contributor guidelines followed
• All formatters and local linters executed and passed
• Written new unit and / or integration tests where applicable
• Protected functional changes with optionality (feature flags)
• Used internationalization (i18n) for all UI strings
• CI builds passed
• Communicated to DevOps any deployment requirements
• Updated any necessary documentation (Confluence, contributing docs) or informed the documentation
  team

🦮 Reviewer guidelines

• 👍 (:+1:) or similar for great changes
• 📝 (:memo:) or ℹ️ (:information_source:) for notes or general info
• ❓ (:question:) for questions
• 🤔 (:thinking:) or 💭 (:thought_balloon:) for more open inquiry that's not quite a confirmed
  issue and could potentially benefit from discussion
• 🎨 (:art:) for suggestions / improvements
• ❌ (:x:) or ⚠️ (:warning:) for more significant problems or concerns needing attention
• 🌱 (:seedling:) or ♻️ (:recycle:) for future improvements or indications of technical debt
• ⛏ (:pick:) for minor or nitpick changes

[github-actions]

Checkmarx One – Scan Summary & Details – c73a7f9b-a1ee-4d70-989c-1cd01303c9dc

Great job! No new security vulnerabilities introduced in this pull request

[codecov]

Codecov Report

❌ Patch coverage is 22.22222% with 7 lines in your changes missing coverage. Please review.
✅ Project coverage is 76.76%. Comparing base (8a7175f) to head (778d1f3).
⚠️ Report is 4 commits behind head on main.

Files with missing lines	Patch %	Lines
crates/bitwarden-fido/src/types.rs	0.00%	6 Missing ⚠️
crates/bitwarden-fido/src/authenticator.rs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #421   +/-   ##
=======================================
  Coverage   76.75%   76.76%           
=======================================
  Files         270      270           
  Lines       25664    25664           
=======================================
+ Hits        19698    19700    +2     
+ Misses       5966     5964    -2     

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[dereknance]

@addisonbeck aside from a unit test or two, this is ready to start looking at. I figured I'd wait to take this PR out of draft until I received a first pass from you.

I went ahead and included fixes for the things that the udeps check was failing on locally. I can totally rip those out if that's undesirable! For whatever reason, they haven't been failing the udeps check in CI.

[addisonbeck]

This looks good to me. I request a review from Dani, since I don't have my name in the commit history of the SDK and he's the expert.

[dani-garcia]

I think the issues you were finding with the static assertions and the elided lifetime were likely caused by using a newer nightly which has some newer lints, rather than by udeps specifically. Seems okay to include them though, they're fairly small anyway.

[dereknance]

I think the issues you were finding with the static assertions and the elided lifetime were likely caused by using a newer nightly which has some newer lints, rather than by udeps specifically. Seems okay to include them though, they're fairly small anyway.

I thought so too, so I tried running the same command with the nightly-2025-08-18 toolchain (since that's what I understand the lint.yml workflow is using) and udeps 0.1.54, but those same unused code bits show up.

At this point I'm curious what it is about my env that is different from CI.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[addisonbeck]

Great job!

[coroiu]

Looks good, nice job 👍