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/map-core-package/proposal.md

@@ -0,0 +1,28 @@
+## Why
+
+Map configuration is scattered across Planner components: tile URLs in `packages/map/src/layers.ts`, color palettes in `ColoredRoute.tsx`, POI categories in `poi-categories.ts`, z-index constants in `z-index.ts`, and overlay configs hardcoded in `PlannerMap.tsx`. This makes it impossible to share map definitions with a future mobile app (MapLibre) or migrate the web to a different renderer without duplicating everything.
+
+## What Changes
+
+- **New `packages/map-core/` package**: Renderer-agnostic map definitions — tile sources, overlay configs, route color palettes, POI category configs, z-index layering constants. Pure TypeScript data, no rendering code, no DOM dependencies.
+- **Refactor `packages/map/`**: Import tile configs from `map-core` instead of defining its own
+- **Refactor Planner components**: Import color palettes, POI categories, and z-index constants from `map-core` instead of defining them locally
+
+## Capabilities
+
+### New Capabilities
+- `map-core`: Shared renderer-agnostic map definitions (tiles, colors, overlays, POI categories, z-index)
+
+### Modified Capabilities
+- `map-display`: Tile layer configs sourced from `map-core` instead of locally defined
+- `route-coloring`: Color palettes and grade functions sourced from `map-core`
+- `osm-poi-overlays`: POI category definitions sourced from `map-core`
+
+## Impact
+
+- New package: `packages/map-core/` added to pnpm workspace and Turborepo
+- `packages/map/src/layers.ts` → thin re-export from `map-core`
+- `apps/planner/app/components/ColoredRoute.tsx` → imports palettes from `map-core`
+- `apps/planner/app/lib/poi-categories.ts` → moves to `map-core`
+- `apps/planner/app/lib/z-index.ts` → moves to `map-core`
+- No user-facing changes — pure refactor