Phase 3: Scale Preparation - API Design, i18n & Multi-Region Support

[tkkr6895]

Description

Prepare the app for multi-region deployment at scale: design the server-side sync REST API (OpenAPI 3.0), scaffold internationalization for Indian regional languages, and design the multi-region data pack system.

Implementation Tasks

• 3.6.1 — Design REST API spec for server-side sync: observation upload/download, species data sync, user auth, conflict resolution — documented as OpenAPI 3.0 YAML (docs/api/sync_api.yaml)
• 3.6.2 — Design multi-region support: region selector on first launch, downloadable data packs per region (boundaries, species checklists, basemap tiles), region pack discovery API (Design only)
• 3.6.3 — Add i18n scaffolding: extract all user-facing strings, create translation file structure for Kannada, Malayalam, Marathi, Tamil (src/i18n/)

Acceptance Criteria

• sync_api.yaml is valid OpenAPI 3.0 with endpoints for:
  • POST /observations — upload observation batch
  • GET /observations — download observations (with filters)
  • POST /sync — bidirectional sync with conflict resolution strategy
  • GET /species — species data sync with region filter
  • POST /auth/login, POST /auth/register — authentication
• API spec aligns with existing SyncEngine queue model and observation schema
• Multi-region design document covers region discovery, pack format, download flow, and storage management
• i18n scaffolding created at src/i18n/ with:
  • en.json — English (default, all strings extracted)
  • Placeholder files for kn.json (Kannada), ml.json (Malayalam), mr.json (Marathi), ta.json (Tamil)
  • Translation loader utility
  • Integration pattern documented for React components
• i18n can be adopted incrementally (components fall back to English)

Dependencies

• SyncEngine (1.4, ✅ complete) — API spec must align with client-side queue model
• Species Database (2.1) — species sync endpoint must match local schema
• Custom Layer system (1.8, ✅ complete) — region packs may include custom layers

Relevant Files

• docs/api/sync_api.yaml (new)
• src/i18n/ (new directory)
• src/services/SyncEngine.ts — client-side sync model reference
• src/types/index.ts — observation/species schema reference
• src/services/SpeciesDatabase.ts — species sync requirements