Add mobile app, map-core, nearby sync, and activity recording specs

mobile-app: Unified React Native + Expo app combining Planner and
Journal. OAuth2 PKCE auth, MapLibre maps, versioned REST API with
Zod schemas, configurable server URL, offline SQLite, Web Push relay
notifications. TanStack Query + Zustand state management. Jest +
Maestro testing. 76 tasks across 5 phases.

map-core-package: Extract renderer-agnostic map definitions (tiles,
color palettes, POI categories, z-index) into @trails-cool/map-core.
Pure refactor preparing for MapLibre on mobile. 27 tasks.

mobile-activity-recording: GPS recording, live stats, HealthKit/Health
Connect export. Separated from mobile-app for independent scheduling.

mobile-nearby-sync: BLE route sync between nearby devices for offline
group riding. QR waypoint sharing as simpler v1. TXQR noted as future.

journal-rest-api spec: Full API contract — endpoints, auth, pagination,
errors, discovery, versioning, BRouter proxy.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

openspec/changes/mobile-app/specs/mobile-app-shell/spec.md

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+## ADDED Requirements
+
+### Requirement: Expo app scaffold
+The system SHALL provide a React Native + Expo managed workflow app at `apps/mobile/` in the monorepo, sharing workspace packages.
+
+#### Scenario: App boots on iOS and Android
+- **WHEN** the app is launched on iOS or Android
+- **THEN** the Expo managed app loads, displays the tab navigation, and renders the Map tab by default
+
+#### Scenario: Monorepo integration
+- **WHEN** the mobile app is built
+- **THEN** it resolves `@trails-cool/types`, `@trails-cool/gpx`, and `@trails-cool/i18n` from pnpm workspace dependencies
+
+### Requirement: Tab navigation
+The system SHALL provide a bottom tab bar with four tabs: Map, Routes, Activities, and Profile.
+
+#### Scenario: Tab switching
+- **WHEN** the user taps a tab (Map, Routes, Activities, or Profile)
+- **THEN** the corresponding screen is displayed and the active tab is visually highlighted
+
+#### Scenario: Tab state preservation
+- **WHEN** the user switches between tabs
+- **THEN** each tab preserves its scroll position and navigation stack
+
+### Requirement: Authentication flow
+The system SHALL require Journal account authentication before accessing protected screens.
+
+#### Scenario: First launch
+- **WHEN** the user opens the app for the first time
+- **THEN** a login screen is shown with the option to enter their Journal instance URL and authenticate
+
+#### Scenario: Session persistence
+- **WHEN** the user has previously authenticated and reopens the app
+- **THEN** stored tokens are loaded from SecureStore and the user is logged in automatically
+
+### Requirement: Deep linking
+The system SHALL handle deep links for opening routes and activities.
+
+#### Scenario: Open route via deep link
+- **WHEN** the app receives a deep link like `trailscool://routes/:id`
+- **THEN** the app navigates to the route detail screen for that route
+
+#### Scenario: Open Planner for collaborative editing
+- **WHEN** the user taps "Edit in Planner" on a route
+- **THEN** the system opens the Planner web URL in the device browser with the appropriate session callback