refactor: consolidate #![allow(clippy::cast_*)] to crate roots

Add the cast-allow block to zesdex-entities/src/lib.rs and
zesdex-utils/src/lib.rs (which lacked it), then remove from
65 sub-files across all 8 crates. Build and all 223 tests
continue to pass.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

crates/zesdex-ipc/src/frame.rs

@@ -9,13 +9,6 @@
 //! The length prefix **excludes** itself — it encodes only the number of
 //! payload bytes that follow.
 
-#![allow(
-    clippy::cast_possible_truncation,
-    clippy::cast_sign_loss,
-    clippy::cast_precision_loss,
-    clippy::cast_possible_wrap
-)]
-
 use anyhow::{Context, Result};
 use std::io::{Read, Write};
 

crates/zesdex-ipc/src/protocol.rs

@@ -5,13 +5,6 @@
 //! [`DaemonFrame`] are serialised as JSON messages framed with a
 //! length prefix (see [`crate::frame`]).
 
-#![allow(
-    clippy::cast_possible_truncation,
-    clippy::cast_sign_loss,
-    clippy::cast_precision_loss,
-    clippy::cast_possible_wrap
-)]
-
 use serde::{Deserialize, Serialize};
 
 // ---------------------------------------------------------------------------

crates/zesdex-ipc/src/server.rs

@@ -4,13 +4,6 @@
 //! [`IpcServer`] wraps a [`UnixListener`] and provides a blocking
 //! `accept` method that returns a [`Connection`] for each new client.
 
-#![allow(
-    clippy::cast_possible_truncation,
-    clippy::cast_sign_loss,
-    clippy::cast_precision_loss,
-    clippy::cast_possible_wrap
-)]
-
 use crate::conn::Connection;
 use anyhow::{Context, Result};
 use std::os::unix::net::UnixListener;