[PM-38443] feat: Add fill-assist per-account storage and constants

[andrebispo5]

🎟️ Tracking

https://bitwarden.atlassian.net/browse/PM-38443

📔 Objective

Adds per-account fillAssistCachedData and fillAssistLastFetchTimestamp storage keys to AppSettingsStore (following the existing serverConfig pattern), fill-assist constants (fillAssistFormsVersion = "v1", fillAssistUpdateInterval = 6h, fillAssistExpectedSchemaMajor = "1"), and clears fill-assist data on account logout.

Depends on #2810 (PR 1/3). This is PR 2/3 for PM-38443. PR 3/3 adds the repository and sync integration.

[github-actions]

🤖 Bitwarden Claude Code Review

Overall Assessment: APPROVE

Reviewed the addition of per-account fillAssistCachedData and fillAssistLastFetchTimestamp storage to AppSettingsStore, the matching mock implementations, the logout-clearing in StateService, and the new fill-assist constants. The changes mirror the existing serverConfig storage pattern precisely (Codable-backed store/fetch helpers, alphabetically-ordered logout clears, mock dictionary semantics). No security, correctness, or breaking-change concerns were found.

Code Review Details

No findings. The implementation correctly follows the established serverConfig storage pattern: the generic store helper removes the UserDefaults key on nil, the new logout clears are placed in alphabetical order alongside the other per-account keys, and the mock setters match the existing setServerConfig semantics. FillAssistCachedData is Codable, satisfying the storage helper constraints.

[Copilot]

Pull request overview

Adds new per-account persistence hooks and shared constants to support Fill-Assist caching and fetch cadence, and ensures Fill-Assist persisted data is cleared on logout. This extends the existing AppSettingsStore per-account storage pattern (e.g., serverConfig) in preparation for the repository/sync work in the next PR.

Changes:

• Added Fill-Assist constants (fillAssistFormsVersion, fillAssistUpdateInterval, fillAssistExpectedSchemaMajor) to shared Constants.
• Added per-account fillAssistCachedData and fillAssistLastFetchTimestamp getters/setters to AppSettingsStore (plus mock + default implementations).
• Cleared Fill-Assist persisted values during account logout in StateService.

Reviewed changes

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

File	Description
BitwardenShared/Core/Platform/Utilities/Constants.swift	Introduces shared Fill-Assist constants for versioning and update interval.
BitwardenShared/Core/Platform/Services/Stores/TestHelpers/MockAppSettingsStore.swift	Adds mock storage + accessors for new per-account Fill-Assist values.
BitwardenShared/Core/Platform/Services/Stores/AppSettingsStore.swift	Extends the settings store protocol and default implementation with per-account Fill-Assist persistence keys.
BitwardenShared/Core/Platform/Services/StateService.swift	Clears Fill-Assist persisted data on account logout.

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 81.20%. Comparing base (61cc961) to head (e76798b).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2811      +/-   ##
==========================================
+ Coverage   81.19%   81.20%   +0.01%     
==========================================
  Files        1026     1026              
  Lines       65799    65817      +18     
==========================================
+ Hits        53425    53447      +22     
+ Misses      12374    12370       -4     

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[fedemkr]

🎨 If you agree I'd like to start adding nested enums here in constants for things that are related like this so we avoid the prefix repetition. We're already doing that with UTType. E.g.

extension Constants {

    /// Fill-Assist constants used by the app.
    ///
    enum FillAssist {
         /// The forms map major version key requested from the manifest (e.g. `"v1"`).
         static let formsVersion = "v1"
          /// ....
    }

So then we can use them by Constants.FillAssist.formsVersion.
I feel like it's better organized this way.

The base branch was changed.