feat: shared pages now appear in sidebar Shared section

Pages with share_mode='anyone' or published=1 are now listed in the
left sidebar Shared section. Icon shows 🌐 for published pages,
🔗 for anyone-with-link pages. Updated _sidebar_data() to query
the pages table for shared/published pages.

app/routers/board.py

@@ -193,10 +193,31 @@ def _sidebar_data(request: Request, owner: str = "", repo: str = "") -> dict:
             "children": [],
         })
 
+    # Load shared pages (anyone with link or published)
+    with get_conn() as conn:
+        shared_rows = conn.execute(
+            "SELECT id, title, workspace, share_mode, published FROM pages "
+            "WHERE share_mode='anyone' OR published=1 ORDER BY updated_at DESC LIMIT 20"
+        ).fetchall()
+    shared_pages = []
+    for r in shared_rows:
+        shared_pages.append({
+            "id": f"page/{r['id']}",
+            "db_id": r["id"],
+            "name": r["title"] or "New page",
+            "icon": "🌐" if r["published"] else "🔗",
+            "url": f"/pages/{r['id']}",
+            "active": False,
+            "indent": 0,
+            "depth": 0,
+            "has_children": False,
+            "children": [],
+        })
+
     return {"workspace_name": ws_name, "workspace_initial": ws_name[0].upper() if ws_name else "B",
             "current_page": repo or "Dashboard", "last_edited": "now",
             "recent_pages": recent, "private_pages": private_items,
-            "favorite_pages": favorites, "shared_pages": [],
+            "favorite_pages": favorites, "shared_pages": shared_pages,
             "user": user, "workspace_key": ws_key}