world books open, and anvils stop offering a cursor gear

- clicking a book in the world opens it and turns its pages: letters and world books share one reader
- the cursor's object rules are the client's own 31-row strategy table now, so decorative objects stop pretending to be usable
- trainer and tradeskill windows draw each row's icon by the reference's own law, and the trainer's filter dropdown toggles again
- water color follows the zone's light blend, so lakes stop snapping between area tints

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

crates/benilla-protocol/src/world/writer/gameobject.rs

@@ -34,4 +34,17 @@ impl WorldWriter {
             &messages::gameobject_query(entry, guid),
         )
     }
+
+    /// Ask for one page of a book (`CMSG_PAGE_TEXT_QUERY`, layout in
+    /// [`messages::page_text_query`]) — the ask-once page cache a readable reaches when the reader
+    /// opens on it (decision 1105). `guid` names the asking object (the book item or the
+    /// `GAMEOBJECT_TYPE_TEXT` world object); the server resolves the page from the id alone.
+    /// Answered by `SMSG_PAGE_TEXT_QUERY_RESPONSE` — once per page of the whole chain, not just
+    /// the one asked for.
+    pub fn page_text_query(&mut self, page_id: u32, guid: u64) -> Result<()> {
+        self.send(
+            opcode::CMSG_PAGE_TEXT_QUERY,
+            &messages::page_text_query(page_id, guid),
+        )
+    }
 }