android: share a note, and read or edit one shared with you

The editor's menu has Share…, which opens a sheet of who the note is shared
with and lets you add someone at view or edit, change it, or stop sharing;
unlinked, it says sharing needs a server. A note shared to view opens
read-only; at edit only its text can change. Cards say who shared a note
("From Robin") or that yours is shared, and a view-only note's boxes don't
tick.

Also: two core store tests used unwrap_err on a Result<Note>, which needs
Note: Debug; they use err().expect() now.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

android/app/src/main/res/values/strings.xml

@@ -58,6 +58,25 @@
     <string name="editor_trash">Move to trash</string>
     <string name="editor_restore">Restore</string>
     <string name="editor_cancel">Cancel</string>
+    <string name="editor_share">Share…</string>
+
+    <!-- Sharing (#5175). Shares live on the server, so the sheet says so when this
+         phone isn't linked to one. -->
+    <string name="share_title">Share</string>
+    <string name="share_loading">Loading…</string>
+    <string name="share_needs_server">Sharing is between people on a server. Link this phone in Sync to share notes.</string>
+    <string name="share_none">Not shared with anyone yet.</string>
+    <string name="share_everyone">Shared with everyone on this server.</string>
+    <string name="share_add">Add someone</string>
+    <string name="share_action">Share</string>
+    <string name="share_remove">Stop sharing</string>
+    <string name="share_can_view">Can view</string>
+    <string name="share_can_edit">Can edit</string>
+    <string name="share_someone">someone</string>
+    <string name="share_by_view_only">Shared by %1$s · view only</string>
+    <string name="share_by_can_edit">Shared by %1$s · you can edit the text</string>
+    <string name="share_chip_shared">Shared</string>
+    <string name="share_chip_by">From %1$s</string>
 
     <!-- Attachments. A file is stored on the phone at once and uploaded on a later
          sync, so nothing here talks about the network. -->