feat: runtime theme switching + second design-token colour theme (selfFridge)

[khoinguyen-mindera]

Ticket

n/a (free-form feature)

Summary

• Second colour theme "selfFridge" generated from the design tokens alongside Alfie. Its surfaces use the Selfridges brand yellow (neutrals-0/100/200) so the switch is clearly visible for testing; dark neutrals stay dark for text contrast.
• Design-token generator (Tools/DesignTokenGen): now parses hex colours, loads each .primitives.* theme mode into its own palette, and emits a ColourPalette struct + AppTheme enum + a ThemeColours.current holder. Primitives.Colours.* became computed forwarders to the active palette — so all ~429 existing call sites reskin with zero edits.
• Persistence + apply: new ThemeService (Model, mirrors ApiEndpointService) persists the selected theme id and soft-reboots via AppDelegate.rebootApp(); AppDelegate.bootstrap applies the palette + UIKit appearance before first render, so the selection survives relaunch.
• Debug menu → Theme picker: lists Alfie / Selfridges, marks the current one, switches on tap. Wired through ServiceProvider → HomeDependencyContainer → DebugMenuViewModel; new AccessibilityID entries.
• Converted 14 static let colour captures (TabControl / ThemedToggle / SizingSwatch) to computed vars so they don't freeze on a soft-reboot.
• Codegen unit tests added (hex parsing, multi-theme emission, schema-drift + empty-colour guards). ThemeService unit tests added.

Verification

• ./Alfie/scripts/verify.sh --skip-integration: build + unit PASSED. Integration was skipped (needs the Alfie-BFF repo as a sibling checkout; unavailable in this worktree) — this change does not touch networking.

Notes / follow-ups

• selfFridge's yellow surfaces are a deliberately bold test palette; can be dialled back to a production-realistic palette on request.
• Swift 6: ThemeColours.current is a mutable non-isolated global (safe today — main-thread only); annotate @MainActor when SharedUI adopts strict concurrency.

Screenshot

[Copilot]

Pull request overview

This PR adds runtime theme switching to Alfie iOS by extending the design-token generator to emit multiple colour palettes (one per .primitives theme mode) and introducing a persisted theme selection that is applied during app bootstrap (and on soft-reboot), so the chosen theme survives relaunch.

Changes:

• Design-token generator now supports multi-theme colour palettes + hex colour parsing, emitting ThemeColours, ColourPalette, and AppTheme while making Primitives.Colours.* forward to the active palette.
• New ThemeService persists the selected theme id and triggers a soft-reboot; app bootstrap applies the persisted theme before first render / appearance setup.
• Debug Menu gains a Theme picker UI and related accessibility identifiers; several UI components switch static colour captures to computed vars to avoid “frozen” colours after reboot.

Reviewed changes

Copilot reviewed 33 out of 33 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
Tools/DesignTokenGen/Tests/DesignTokenGenCoreTests/GeneratorTests.swift	Adds tests for multi-theme loading, hex parsing, and multi-theme emission/guards.
Tools/DesignTokenGen/Tests/DesignTokenGenCoreTests/Fixtures/mini/manifest.json	Extends mini fixture to include a second .primitives theme mode.
Tools/DesignTokenGen/Tests/DesignTokenGenCoreTests/Fixtures/mini/.primitives.selffridge-theme.tokens.json	Adds mini fixture token file for the second theme (hex colours).
Tools/DesignTokenGen/Tests/DesignTokenGenCoreTests/CoverageTests.swift	Updates expected written files and adjusts colour literal tests to target ThemeColours.
Tools/DesignTokenGen/Sources/DesignTokenGenCore/TokenLoader.swift	Loads per-theme colour palettes, adds .primitives theme mode handling, and parses hex colour strings.
Tools/DesignTokenGen/Sources/DesignTokenGenCore/Token.swift	Adds TokenValue.isColour helper for filtering colour tokens.
Tools/DesignTokenGen/Sources/DesignTokenGenCore/Emitter.swift	Emits new ThemeColours+Generated.swift and changes colours/semantic tokens to computed forwarders.
Alfie/AlfieKit/Tests/ModelTests/ThemeServiceTests.swift	Adds unit tests for theme persistence + reboot triggering.
Alfie/AlfieKit/Tests/DebugMenuTests/ThemePickerViewModelTests.swift	Adds unit tests for theme picker view model behavior.
Alfie/AlfieKit/Sources/SharedUI/Theme/Toggle/ThemedToggleView.swift	Converts captured theme colours to computed vars to reflect runtime theme switches.
Alfie/AlfieKit/Sources/SharedUI/Theme/Components/SizingBanner/SizingSwatchView.swift	Converts a captured colour constant to computed to avoid caching across reboot.
Alfie/AlfieKit/Sources/SharedUI/GeneratedTokens/ThemeColours+Generated.swift	New generated multi-theme palette holder + AppTheme enum.
Alfie/AlfieKit/Sources/SharedUI/GeneratedTokens/Theme+Generated.swift	Changes semantic colour tokens to computed vars so they track active theme.
Alfie/AlfieKit/Sources/SharedUI/GeneratedTokens/Primitives+Generated.swift	Changes primitive colours to forward to ThemeColours.current.
Alfie/AlfieKit/Sources/SharedUI/DesignTokens/manifest.json	Adds second .primitives theme mode for SharedUI token set.
Alfie/AlfieKit/Sources/SharedUI/DesignTokens/.primitives.selffridge-theme.tokens.json	Adds second theme primitive colour token set (hex colours).
Alfie/AlfieKit/Sources/SharedUI/Components/TabControl/TabControl.swift	Converts captured colours to computed vars for runtime theme switching.
Alfie/AlfieKit/Sources/Model/Services/Theme/ThemeServiceProtocol.swift	Introduces service protocol for persisting theme id and rebooting.
Alfie/AlfieKit/Sources/Model/Services/Theme/ThemeService.swift	Implements ThemeService backed by UserDefaults.
Alfie/AlfieKit/Sources/Model/Services/ServiceProviderProtocol.swift	Exposes themeService on the service provider protocol.
Alfie/AlfieKit/Sources/Mocks/Core/Services/MockThemeService.swift	Adds mock implementation for tests and previews.
Alfie/AlfieKit/Sources/Mocks/Core/Services/MockServiceProvider.swift	Wires themeService into mock provider.
Alfie/AlfieKit/Sources/Home/UI/HomeViewModel.swift	Passes themeService through to DebugMenu construction.
Alfie/AlfieKit/Sources/Home/Models/HomeDependencyContainer.swift	Adds themeService to Home dependency container.
Alfie/AlfieKit/Sources/DebugMenu/UI/Theme/ThemePickerViewModel.swift	Implements theme picker logic using AppTheme + ThemeServiceProtocol.
Alfie/AlfieKit/Sources/DebugMenu/UI/Theme/ThemePickerView.swift	Adds Theme picker UI list with selection checkmark + accessibility ids.
Alfie/AlfieKit/Sources/DebugMenu/UI/DebugMenuViewModel.swift	Adds themeService dependency to DebugMenu view model.
Alfie/AlfieKit/Sources/DebugMenu/UI/DebugMenuView.swift	Adds Theme entry to Debug Menu navigation and wires ThemePickerView.
Alfie/AlfieKit/Sources/AppFeature/Navigation/AppFeatureViewModel.swift	Injects themeService into Home flow dependencies.
Alfie/AlfieKit/Sources/AccessibilityIdentifiers/AccessibilityID.swift	Adds accessibility identifiers for Debug Menu theme picker.
Alfie/AlfieKit/Package.swift	Updates module dependencies for new DebugMenu/theme picker and tests.
Alfie/Alfie/Service/ServiceProvider.swift	Instantiates and exposes ThemeService in app service provider.
Alfie/Alfie/Delegate/AppDelegate.swift	Applies persisted theme during bootstrap before first UI render / appearance setup.