docs: add mobile-ux session learnings and shared partial architecture

CLAUDE.md

@@ -35,6 +35,28 @@ The site is structured around Trip entities. Key facts:
 - GPX route files live as media on the trip page itself, served via leaflet-gpx CDN
 - Manage GPX files (view/upload/delete) at `/gpx-manager` — requires admin login; filenames are auto-slugified on upload
 
+### Shared feed-map partial
+
+The mini-map above the feed is shared across two pages via a Twig partial:
+
+- **Partial:** `user/themes/intotheeast/templates/partials/feed-map.html.twig`
+- **Used by:** `dailies.html.twig` and `stories.html.twig`
+- **NOT used by:** `trip.html.twig` (uses its own `#trip-map` / `.home-map-col` layout)
+
+**Parameters (passed via `{% include ... with {...} only %}`):**
+
+| Parameter | Type | Description |
+|---|---|---|
+| `map_entries` | array | `[{lat, lng, title, slug, url, type, force_connect, transport_mode}]` |
+| `map_id` | string | HTML id for map div: `'feed-map'` or `'stories-map'` |
+| `map_var` | string | JS global variable: `'feedMap'` or `'storiesMap'` |
+| `link_href` | string\|null | "View full map" link URL; `null` hides it |
+| `card_prefix` | string | Scroll-to ID prefix: `'entry-'` (dailies) or `'story-'` (stories) |
+| `trip_page` | Page | Trip page object for autoconnect setting |
+| `show_journey` | bool | `true` draws the route connector; `false` skips it |
+
+The partial always: starts attribution collapsed, shows the fullscreen button (mobile-only, CSS `display:none` ≥769px), and on marker click scrolls to `#<card_prefix><slug>` + flashes `.is-highlighted`.
+
 ### GPX file management
 
 GPX files are stored as page media on the trip page (`user/pages/01.trips/<slug>/`). They are picked up automatically by `map.html.twig` via `trip_page.media.all`.