feat: OS Share Target for recipe URLs (v0.67.0)

Declares share_target in manifest.ts (action /recipes, GET,
title/text/url params). recipes/page.tsx extracts the shared link --
preferring the url param, falling back to the first http(s) URL
found inside text since senders vary on where they put it -- and
passes it to RecipesHeader as sharedUrl. UrlImportDialog gained
initialUrl/autoImport props so the existing import-from-URL flow
opens pre-filled and fires immediately instead of requiring the user
to paste the link back in.

Chromium/Android only -- Safari has no Share Target API at all,
same restriction already documented for the install-prompt banner.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/web/app/manifest.ts

@@ -15,5 +15,18 @@ export default function manifest(): MetadataRoute.Manifest {
       { src: "/icon-512.svg", sizes: "512x512", type: "image/svg+xml", purpose: "any" },
       { src: "/icon-512.svg", sizes: "512x512", type: "image/svg+xml", purpose: "maskable" },
     ],
+    // Registers Epicure as a share target in the OS share sheet (Chromium
+    // on Android/desktop once installed — Safari has no equivalent API).
+    // Sharing a recipe link from another app opens /recipes with these
+    // query params, which auto-opens the URL-import dialog pre-filled.
+    share_target: {
+      action: "/recipes",
+      method: "GET",
+      params: {
+        title: "title",
+        text: "text",
+        url: "url",
+      },
+    },
   };
 }