ui: remove duplicate add buttons from empty states; fix subtitle wrap…

[pexatar]

…ping and alignment

• Remove PrimaryActionText from all four list-view EmptyStateControls (Passwords, CreditCards, Identities, SecureNotes) — the add action is already available in the top-right toolbar; showing it a second time at the center of the page was redundant and visually cluttered
• Remove wired PrimaryActionCommand in IdentitiesListView and SecureNotesListView code-behind (no longer needed)
• Hide ColumnHeadersGrid in PasswordsListView when the list is empty to prevent the header row from pushing the empty state off-center
• EmptyStateControl: remove MaxWidth constraint and set TextWrapping=NoWrap on the subtitle so it always renders on a single line
• IdentitiesListView: add Margin="0,16,0,0" to EmptyState to compensate for the missing RowSpacing gap and align its icon with Password/Cards
• Installer/PassKey.iss: bump AppVersion to 1.0.5 (missed in previous PR)

Description

Brief description of the changes in this PR.

Type of change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update
• Refactoring (no functional changes)

Testing

Describe the tests you ran to verify your changes.

• All existing tests pass (dotnet test)
• New tests added for new functionality
• Solution builds without warnings (dotnet build PassKey.sln -p:Platform=x64)

Checklist

• My code follows the project's code style guidelines
• I have added XML documentation to all new public types and members
• I have updated the CHANGELOG.md if applicable
• My changes do not introduce new compiler warnings