refactor(console): reland oapiClient view-layer migration (supersedes #241)

[jeroenrinzema]

Summary

This relands the salvageable part of #241. Most of #241's diff already landed on main via other PRs; merging #241 as-is would revert main's Access/clients feature and resurrect deleted files. The genuinely useful net delta is the view-layer migration from the legacy API client to the generated OpenAPI client (oapiClient) on files that main has not touched since #241 forked (merge-base 1683f7e0).

For those files, taking #241's version applies only the client migration with zero conflict. This PR relands exactly that subset.

Files relanded (20)

These were migrated only by #241; main still runs them on the legacy client:

• console/src/components/locale/select.tsx
• console/src/components/media-manager/MediaManager.tsx
• console/src/lib/path-suggestions.ts
• console/src/validation/settings/api-key-dialog.ts
• console/src/views/campaign/CampaignVariableContext.tsx
• console/src/views/campaign/template/mail/editor/hooks/useSendTestEmail.ts
• console/src/views/campaign/template/text/useSendTestSMS.ts
• console/src/views/journey/JourneyUserSelectionModal.tsx
• console/src/views/journey/JourneyVariableContext.tsx
• console/src/views/project/GettingStarted.tsx
• console/src/views/project/ProjectOnboardingGettingStarted.tsx
• console/src/views/project/ProjectOnboardingIntegration.tsx
• console/src/views/project/ProjectOnboardingUsers.tsx
• console/src/views/project/Projects.tsx
• console/src/views/settings/EventSchemas.tsx
• console/src/views/settings/Locales.tsx
• console/src/views/settings/ProjectSettings.tsx
• console/src/views/users/UserDetailJourneys.tsx
• console/src/views/users/UserDetailSubscriptions.tsx
• console/src/views/users/rules/RuleBuilder.tsx

Verification

Verified tsc-clean against main's baseline:

• Baseline (origin/main, tsc -p tsconfig.app.json --noEmit): 125 pre-existing errors.
• With this reland: 124 errors. Zero new type errors introduced; this reland actually fixes one pre-existing error (MediaManager.tsx SearchResult<Image>.data).
• ESLint on the 20 relanded files: clean (no errors, no new warnings).

Files that could NOT be cleanly relanded (dropped, 12)

These were part of #241's view migration but depend on #241's version of deferred/conflict files (notably the migrated console/src/types.ts and the generated OpenAPI symbols). On main's legacy types.ts, #241's casts/assignments to Template / User / Journey / Campaign / List / Project / JourneyStepMap no longer overlap, producing new TS2352/TS2322/TS2345 errors. They were reverted to main's version to keep this PR tsc-clean and need a manual re-migration on top of main:

• console/src/components/app-sidebar.tsx
• console/src/views/campaign/template/Content.tsx
• console/src/views/campaign/template/Review.tsx
• console/src/views/campaign/template/Template.tsx
• console/src/views/campaign/template/UserSelection.tsx
• console/src/views/campaign/template/mail/editor/hooks/useTemplatePersistence.ts
• console/src/views/journey/components/JourneyEditorToolbar.tsx
• console/src/views/journey/editor/JourneyEditor.tsx
• console/src/views/journey/hooks/useJourneyPersistence.ts
• console/src/views/journey/steps/Campaign.tsx
• console/src/views/users/ListDetail.tsx
• console/src/views/users/UserLookup.tsx

Supersedes #241.