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SvelteKit +page.server.ts to universal +page.ts conversion for Capacitor mobile apps

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TL;DR.

Gotchas when converting SvelteKit server loads to universal loads for Capacitor: locals unavailable, server imports fail, timezone APIs survive, type gaps hide in loader but surface in components.

When converting SvelteKit routes from +page.server.ts to universal +page.ts for Capacitor compatibility, watch for server-only APIs that silently work differently in universal context:

  1. locals is unavailableevent.locals.user doesn't exist in universal loads. Move user context to a client-side store (get_ctx()) and consume it in the component instead of the loader return value.

  2. logger from server modules$lib/server/* imports fail in universal loads. Replace with console.error.

  3. Timezone-dependent computations survivenew Date().toLocaleDateString('en-CA', { timeZone: 'America/New_York' }) works identically in browser JS, so server-computed timezone values can move to universal loads without change.

  4. Type safety gap — TypeScript won't catch the locals removal at the loader level because PageLoad simply doesn't have locals in its type. But downstream components referencing data.self_username (removed from return) will fail at svelte-check time. Always run svelte-check after conversion, not just tsc.

  5. Pair with webPathToMobile — Even after converting to universal loads, mobile routes may still benefit from redirection to a dedicated mobile page (e.g., /pulse/m/explore where pulse is embedded with bottom tabs). The universal load conversion makes the web route work in-app; the redirect makes it good in-app.

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