Improve illustrations and migration steps UI

[lmuntaner]

Motivation

Address comments raised in #3245

Changes

• Replaced the inline SVG in MigrationIllustration.svelte with a flex layout using three components: LogoLegacy, ArrowRight, and the new Logo, making the illustration more modular and maintainable. (MigrationIllustration.svelte, LogoLegacy.svelte)
• Updated SmileyWritingIllustration.svelte to use a simplified, modern SVG illustration with a new layout and removed legacy code. (SmileyWritingIllustration.svelte)
• Adjusted the layout in migration wizard views to wrap illustrations in flex containers for better alignment and spacing. (CreatePasskeyMigration.svelte, EnterIdentityNumber.svelte)
• Enhanced the identity number input to restrict input to numeric values only, improving accessibility and preventing user errors. (EnterIdentityNumber.svelte)
• Added autofocus to key input fields and provided a helpful hint for the passkey name input, guiding users to pick a recognizable name. (CreatePasskeyMigration.svelte, EnterIdentityNumber.svelte)
• Updated the support button to use the centralized SUPPORT_URL constant instead of a hardcoded URL, improving maintainability. (EnterIdentityNumber.svelte)

Tests

Tested locally that the migration flow is still rendered as expected in both themes and mobile

[Copilot]

Pull Request Overview

This PR improves the UI and user experience of the migration wizard flow by replacing complex inline SVG illustrations with modular components, enhancing input validation, and improving accessibility. The changes focus on making the migration process more user-friendly and maintainable.

• Replaced inline SVG illustrations with modular flex-based components for better maintainability
• Enhanced form input validation and accessibility with numeric-only input and autofocus
• Added helpful UI hints and centralized configuration usage

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
EnterIdentityNumber.svelte	Added numeric input validation, autofocus, and centralized support URL usage
CreatePasskeyMigration.svelte	Added autofocus and helpful hint for passkey name input
SmileyWritingIllustration.svelte	Simplified SVG illustration with modern, cleaner design
MigrationIllustration.svelte	Replaced complex inline SVG with modular flex layout using separate components
LogoLegacy.svelte	New component containing the legacy logo SVG for the migration illustration

Comments suppressed due to low confidence (1)

src/frontend/src/lib/components/wizards/migration/views/EnterIdentityNumber.svelte:84

• The 'type="number"' attribute is being removed but the line is still shown in the diff. This appears to be an inconsistency in the diff representation, as the input validation logic suggests this should be a text input with custom numeric validation.

      size="md"

[sea-snake]

LGTM