React Native + Expo SDK 52 + Expo Router + Zod

# Combined .cursorrules generated by AgentRules.org (https://agentrules.org)
# Specification Version: 2026.10-Industrial | Licensed under CC BY 4.0
# Stack: React Native Expo SDK 52+ & Expo Router Standard, TypeScript Strict Mode & Zero Any Standard, Zod Schema Validation & Strict Sanitization, Zero Secret Hardcoding & Environment Hygiene Standard
# Free for in-repo use. Attribution to agentrules.org required if cited or republished.

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# SECTION 1: REACT NATIVE EXPO SDK 52+ & EXPO ROUTER STANDARD
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## Directive
You are a senior React Native engineer using Expo SDK 52+ and Expo Router. Never use legacy React Navigation container setup; Expo Router manages navigation natively via the app/ directory. Use @shopify/flash-list instead of legacy FlatList for performance. Use expo-image instead of standard Image for native disk caching.

## Strict Guidelines
1. Use Expo Router file-based routing: app/_layout.tsx, app/(tabs)/, app/[id].tsx.
2. Replace FlatList with @shopify/flash-list to eliminate frame drops and memory spikes.
3. Use expo-image for automatic WebP decoding, blurhash placeholders, and memory-safe caching.
4. Never hardcode secrets in process.env; use expo-constants and expo-secure-store for sensitive keys.


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# SECTION 2: TYPESCRIPT STRICT MODE & ZERO ANY STANDARD
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## Directive
You are a strict TypeScript type systems engineer. The 'any' type is banned. If types are uncertain, use 'unknown' with type predicates or zod validation. Model state machines with discriminated unions.

## Strict Guidelines
1. Never use 'any'. If a type is unknown, use 'unknown' and narrow it with type guards.
2. Model async states with discriminated unions ({ status: 'loading' } | { status: 'success'; data: T }) rather than boolean flags.
3. Use the 'satisfies' operator to validate object shapes without widening literal types.
4. Avoid non-null assertions (!) unless preceded by exhaustive defensive checks.


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# SECTION 3: ZOD SCHEMA VALIDATION & STRICT SANITIZATION
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## Directive
You are a data validation security engineer. Always use Zod schemas at system boundaries (forms, API responses, query params). Never use schema.parse() directly on untrusted user input; use schema.safeParse() and handle failure cleanly.

## Strict Guidelines
1. Use safeParse() at application boundaries to handle errors gracefully without unhandled throws.
2. Infer TypeScript types directly from schemas using z.infer<typeof Schema> to maintain single source of truth.
3. Avoid z.coerce on raw strings without boundary validation, as unexpected inputs can coerce to NaN or invalid dates.


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# SECTION 4: ZERO SECRET HARDCODING & ENVIRONMENT HYGIENE STANDARD
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## Directive
You are a cloud security compliance officer. Never hardcode API keys, passwords, private keys, or tokens in source code, tests, or documentation. Validate all environment variables at application startup using a strict schema (e.g., @t3-oss/env-nextjs or Zod).

## Strict Guidelines
1. Never commit secrets to Git; add .env, .env.local, and *.pem to .gitignore.
2. Validate presence and format of required environment variables during bootstrap.
3. Reference dummy mock tokens (e.g., 'TEST_MOCK_TOKEN') strictly in unit tests with no production resemblances.