fix(ui): address PR review comments

- inputwin.c: improve MB_CUR_MAX error message with actionable advice
- inputwin.c: add log_error when input window pad allocation fails
- statusbar.c: add log_warning for invalid cols values
- window.c: simplify _check_subwin_width using CLAMP macro

src/database.c

@@ -77,6 +77,8 @@ _db_teardown(const char* ctx)
         }
         g_chatlog_database = NULL;
     }
+    // Safe to call unconditionally; no-op if not initialized.
+    // See: https://www.sqlite.org/c3ref/initialize.html
     sqlite3_shutdown();
 }