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-utils/src/error.rs

@@ -1,10 +1,3 @@
-#![allow(
-    clippy::cast_possible_truncation,
-    clippy::cast_sign_loss,
-    clippy::cast_precision_loss,
-    clippy::cast_possible_wrap
-)]
-
 use std::fmt;
 
 /// Unified error type for the zesdex codebase.

crates/zesdex-utils/src/lib.rs

@@ -1,3 +1,10 @@
+#![allow(
+    clippy::cast_possible_truncation,
+    clippy::cast_sign_loss,
+    clippy::cast_precision_loss,
+    clippy::cast_possible_wrap
+)]
+
 pub mod atomic_write;
 pub use atomic_write::write_json_atomic;
 pub mod clipboard;

crates/zesdex-utils/src/pagination.rs

@@ -1,10 +1,3 @@
-#![allow(
-    clippy::cast_possible_truncation,
-    clippy::cast_sign_loss,
-    clippy::cast_precision_loss,
-    clippy::cast_possible_wrap
-)]
-
 use serde::{Deserialize, Serialize};
 
 /// A generic paginated response.

crates/zesdex-utils/src/sanitize.rs

@@ -1,10 +1,3 @@
-#![allow(
-    clippy::cast_possible_truncation,
-    clippy::cast_sign_loss,
-    clippy::cast_precision_loss,
-    clippy::cast_possible_wrap
-)]
-
 /// Characters that are invalid in filenames on most operating systems.
 const INVALID_FILENAME_CHARS: &[char] = &[
     '/', '\0', '<', '>', ':', '"', '\\', '|', '?', '*', '\x01', '\x02', '\x03', '\x04', '\x05',

crates/zesdex-utils/src/slug.rs

@@ -1,10 +1,3 @@
-#![allow(
-    clippy::cast_possible_truncation,
-    clippy::cast_sign_loss,
-    clippy::cast_precision_loss,
-    clippy::cast_possible_wrap
-)]
-
 use std::path::{Path, PathBuf};
 
 const MAX_SLUG_LENGTH: usize = 80;