Version history of password notes

[mzagozda]

No description provided.

[Copilot]

Pull request overview

Adds a version history feature for entries (password notes) so users can view prior versions in the entry Details page, while keeping existing stored data backward-compatible via a migration step.

Changes:

• Introduces EntryHistoryRecord and adds a History collection to Entry.
• Persists history on create/update and migrates existing entries to include a synthetic “pre-history” record.
• Renders an expandable “Change history” timeline in the Details view with supporting CSS styling.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
wwwroot/css/site.css	Adds styles for the history timeline UI in the entry Details view.
Views/Entries/Details.cshtml	Adds an expandable history section that lists versions sorted by change timestamp.
Services/JsonDataStore.cs	Writes history records on create/update, migrates older entries, and adjusts JSON deserialization options.
Models/EntryHistoryRecord.cs	New model representing a single historical version snapshot.
Models/Entry.cs	Adds History collection to the entry model.

---

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

[Copilot]

History is declared as a non-nullable List<EntryHistoryRecord>, but other code paths treat it as potentially null (e.g., History ??= ..., History == null, and Model.History ?? ...). With nullable reference types enabled, this will produce warnings and makes the nullability contract unclear. Consider either making History nullable (List<EntryHistoryRecord>?) to match the persisted/deserialized reality, or enforce non-nullability by removing the null checks and ensuring migration/deserialization always produces a non-null list (including handling "History": null in stored JSON).

Suggested change

	public List<EntryHistoryRecord> History { get; set; } = new();
	public List<EntryHistoryRecord>? History { get; set; } = new();

[Copilot]

entry.History ??= ... assumes History can be null, but Entry.History is currently non-nullable. With <Nullable>enable</Nullable>, this will trigger warnings and obscures the intended nullability contract. Align this by either making Entry.History nullable or by removing the null-coalescing and relying on a guaranteed non-null list after deserialization/migration.

Suggested change

	entry.History ??= new List<EntryHistoryRecord>();
	entry.History.Add(new EntryHistoryRecord
	{
	var history = entry.History;
	if (history == null)
	{
	history = new List<EntryHistoryRecord>();
	entry.History = history;
	}
	history.Add(new EntryHistoryRecord
	{