Add Phase 4 master plan and install leaflet dependency

Write the flights-map master plan covering sub-plans 4A-4D.
Add leaflet + @types/leaflet to support the map canvas component.

docs/superpowers/plans/2026-04-15-phase-4-flights-map-master.md

@@ -0,0 +1,77 @@
+# Phase 4 -- Flights Map (Master Plan)
+
+## Goal
+
+Port the Angular `flights-map` feature (single `/flights-map` route) to the React/ModernJS codebase as a Module Federation remote component. The map uses Leaflet for interactive marker/polyline rendering and is behind the `flightsMap` feature flag.
+
+## Angular analysis summary
+
+- **Route:** `/flights-map` (start page with embedded Leaflet map)
+- **Feature flag:** `flightsMap` (env-based)
+- **APIs:** `destinations/v1` (search routes by departure/arrival), `days/.../flights-map/v1` (calendar availability)
+- **Leaflet map:** markers (blue default, blue-small zoom-dependent, orange selected), polylines (solid direct, dashed connecting), popups, tooltips, zoom-aware layer visibility
+- **Components:** start page container, map body (sole Leaflet consumer), filter panel, meta tags, loader/empty overlays
+- **No SignalR** -- data is static, fetched on filter change
+- **SEO:** meta tags only in Angular; design spec requires JSON-LD `WebPage` schema
+
+## Sub-plans
+
+### 4A -- Types + API + Hooks
+
+**Files:** `src/features/flights-map/types.ts`, `api.ts`, `api.test.ts`, `hooks/useFlightsMapSearch.ts`, `hooks/useFlightsMapCalendar.ts`
+
+- Define `IFlightRoute`, `IMapMarker`, `IMapPolyline`, `FlightsMapSearchParams`, `FlightsMapCalendarParams`
+- Define `IDestinationsResponse`, `IFlightsMapDaysResponse`
+- API: `searchDestinations(client, params)` -> `GET destinations/1`, `getFlightsMapCalendar(client, params)` -> `GET days/{date}/200/{route}/flights-map/v1`
+- Hooks: `useFlightsMapSearch(params)`, `useFlightsMapCalendar(params)`
+- Feature flag: `useFeatureFlag("flightsMap")` via env config
+- TDD: ~10 tests for API functions
+
+### 4B -- Leaflet Map Wrapper
+
+**File:** `src/features/flights-map/components/MapCanvas.tsx`
+
+- **Only file that imports `leaflet`** (design spec constraint)
+- Wrapped in `React.lazy()` + `<ClientOnly>` (SSR-safe)
+- Accepts `markers`, `polylines`, `onMarkerClick` etc. as props -- does not own state
+- Renders markers (blue/orange icons), polylines (solid/dashed), popups, tooltips
+- Great-circle arc calculation for polyline rendering
+- Install `leaflet` + `@types/leaflet`
+- No TDD (Leaflet requires real DOM)
+
+### 4C -- Route Pages + Feature Components
+
+**Files:**
+- `src/routes/[lang]/flights-map/page.tsx` -- route page with SEO + feature flag guard
+- `src/features/flights-map/components/FlightsMapStartPage.tsx` -- container (filter + map + loading/empty states)
+- `src/features/flights-map/components/FlightsMapFilter.tsx` -- search filter (departure, arrival, connections, domestic/international toggles, date picker)
+- `src/features/flights-map/components/ClientOnly.tsx` -- SSR-safe wrapper
+
+### 4D -- SEO + JSON-LD + Parity
+
+**Files:**
+- `src/features/flights-map/seo.ts` -- `buildFlightsMapSeo(t, locale, canonicalOrigin)`
+- `src/features/flights-map/json-ld.ts` -- JSON-LD `WebPage` schema builder
+- `src/features/flights-map/seo.test.ts` -- ~5 integration tests
+- Update barrel `src/features/flights-map/index.ts`
+- Update `src/mf/expose/FlightsMap.tsx` from stub to real
+
+## Dependency graph
+
+```
+4A (types/api/hooks) --> 4B (map canvas, needs types)
+                     --> 4C (pages/components, needs hooks)
+4A + 4B + 4C --------> 4D (SEO + barrel + MF expose update)
+```
+
+## Verification
+
+```bash
+pnpm typecheck && pnpm lint && pnpm test && pnpm build:standalone
+```
+
+## Constraints
+
+- Do NOT touch `ClientApp/`, ASP.NET, `wwwroot/`
+- No `Co-Authored-By` lines in commits
+- ~8-12 commits total

package.json

@@ -35,6 +35,7 @@
     "i18next-icu": "^2.0.0",
     "i18next-resources-to-backend": "^1.0.0",
     "intl-messageformat": "^10.0.0",
+    "leaflet": "^1.9.4",
     "lru-cache": "^10.0.0",
     "react": "^18.2.0",
     "react-dom": "^18.2.0",
@@ -48,6 +49,7 @@
     "@testing-library/jest-dom": "^6",
     "@testing-library/react": "^16.3.2",
     "@testing-library/react-hooks": "^8.0.1",
+    "@types/leaflet": "^1.9.21",
     "@types/node": "^24.0.0",
     "@types/react": "^18.2.0",
     "@types/react-dom": "^18.2.0",

pnpm-lock.yaml

@@ -50,6 +50,9 @@ importers:
       intl-messageformat:
         specifier: ^10.0.0
         version: 10.7.18
+      leaflet:
+        specifier: ^1.9.4
+        version: 1.9.4
       lru-cache:
         specifier: ^10.0.0
         version: 10.4.3
@@ -84,6 +87,9 @@ importers:
       '@testing-library/react-hooks':
         specifier: ^8.0.1
         version: 8.0.1(@types/react@18.3.28)(react-dom@18.3.1(react@18.3.1))(react-test-renderer@19.2.5(react@18.3.1))(react@18.3.1)
+      '@types/leaflet':
+        specifier: ^1.9.21
+        version: 1.9.21
       '@types/node':
         specifier: ^24.0.0
         version: 24.12.2
@@ -2711,6 +2717,9 @@ packages:
   '@types/estree@1.0.8':
     resolution: {integrity: sha512-dWHzHa2WqEXI/O1E9OjrocMTKJl2mSrEolh1Iomrv6U+JuNwaHXsXx9bLu5gG7BUWFIN0skIQJQ/L1rIex4X6w==}
 
+  '@types/geojson@7946.0.16':
+    resolution: {integrity: sha512-6C8nqWur3j98U6+lXDfTUWIfgvZU+EumvpHKcYjujKH7woYyLj2sUmff0tRhrqM7BohUw7Pz3ZB1jj2gW9Fvmg==}
+
   '@types/html-minifier-terser@6.1.0':
     resolution: {integrity: sha512-oh/6byDPnL1zeNXFrDXFLyZjkr1MsBG667IM792caf1L2UPOOMf65NFzjUH/ltyfwjAGfs1rsX1eftK0jC/KIg==}
 
@@ -2726,6 +2735,9 @@ packages:
   '@types/json-schema@7.0.15':
     resolution: {integrity: sha512-5+fP8P8MFNC+AyZCDxrB2pkZFPGzqQWUzpSeuuVLvm8VMcorNYavBqoFcxK8bQz4Qsbn4oUEEem4wDLfcysGHA==}
 
+  '@types/leaflet@1.9.21':
+    resolution: {integrity: sha512-TbAd9DaPGSnzp6QvtYngntMZgcRk+igFELwR2N99XZn7RXUdKgsXMR+28bUO0rPsWp8MIu/f47luLIQuSLYv/w==}
+
   '@types/loadable__component@5.13.10':
     resolution: {integrity: sha512-2/LjmgG1JcGPj7T3NViq7BB5cvOA0s63gL3Gv+FPULj2L+3ExWfsNQcsFPUIOoGsVUJeZxgNPf320JZDyxjtCQ==}
 
@@ -4435,6 +4447,9 @@ packages:
     resolution: {integrity: sha512-dcS1ul+9tmeD95T+x28/ehLgd9mENa3LsvDTtzm3vyBEO7RPptvAD+t44WVXaUjTBRcrpFeFlC8WCruUR456hw==}
     engines: {node: '>=0.10.0'}
 
+  leaflet@1.9.4:
+    resolution: {integrity: sha512-nxS1ynzJOmOlHp+iL3FyWqK89GtNL8U8rvlMOsQdTTssxZwCXh8N2NB3GDQOL+YR3XnWyZAxwQixURb+FA74PA==}
+
   levn@0.4.1:
     resolution: {integrity: sha512-+bT2uH4E5LGE7h/n3evcS/sQlJXCpIp6ym8OWJ5eV6+67Dsql/LaaT7qJBAt2rzfoa/5QBGBhxDix1dMt2kQKQ==}
     engines: {node: '>= 0.8.0'}
@@ -9701,6 +9716,8 @@ snapshots:
 
   '@types/estree@1.0.8': {}
 
+  '@types/geojson@7946.0.16': {}
+
   '@types/html-minifier-terser@6.1.0': {}
 
   '@types/istanbul-lib-coverage@2.0.6': {}
@@ -9715,6 +9732,10 @@ snapshots:
 
   '@types/json-schema@7.0.15': {}
 
+  '@types/leaflet@1.9.21':
+    dependencies:
+      '@types/geojson': 7946.0.16
+
   '@types/loadable__component@5.13.10':
     dependencies:
       '@types/react': 18.3.28
@@ -11708,6 +11729,8 @@ snapshots:
 
   kind-of@6.0.3: {}
 
+  leaflet@1.9.4: {}
+
   levn@0.4.1:
     dependencies:
       prelude-ls: 1.2.1