feat(search): add game search page (#50)

Add /search to find games by name on IGDB.
A game in the library opens its game page. Other hits open a
detail view with an Add button. The query stays in the URL.
To fit the new nav icon on 360 px phones, the header padding is
smaller and the points chip hides while the Questions icon shows.

README.md

@@ -92,6 +92,8 @@ flowchart LR
 - **Add a game by name** for games outside Steam (PlayStation, Switch, Xbox, physical): search IGDB, pick a hit,
   a platform and optional hours. Works without a Steam ID. Games already in ToBePlayed come first. Check several
   hits to add them at once through the import review.
+  The **Search** page (`/search`, nav item "Search") finds games by name: results with cover, year, platforms and an
+  "In library" badge; an own game opens its game page, any other hit opens a detail view with "Add".
 - **Import** (`/import`): a list (one title per line) or a CSV (title, platform, hours or minutes, status). Core
   matches the lines with IGDB and saves them in the background; the page shows the steps (queued with the imports
   before yours, searching on IGDB, your review, adding to the library, time to beat and moods, done) with the