Refactor proxy and transport modules for improved safety and performance

- Enhanced linting rules in `src/proxy/mod.rs` to enforce stricter code quality checks in production.
- Updated hash functions in `src/proxy/middle_relay.rs` for better efficiency.
- Added new security tests in `src/proxy/tests/middle_relay_stub_completion_security_tests.rs` to validate desynchronization behavior.
- Removed ignored test stubs in `src/proxy/tests/middle_relay_security_tests.rs` to clean up the test suite.
- Improved error handling and code readability in various transport modules, including `src/transport/middle_proxy/config_updater.rs` and `src/transport/middle_proxy/pool.rs`.
- Introduced new padding functions in `src/stream/frame_stream_padding_security_tests.rs` to ensure consistent behavior across different implementations.
- Adjusted TLS stream validation in `src/stream/tls_stream.rs` for better boundary checking.
- General code cleanup and dead code elimination across multiple files to enhance maintainability.

src/proxy/mod.rs

@@ -1,5 +1,63 @@
 //! Proxy Defs
 
+// Apply strict linting to proxy production code while keeping test builds noise-tolerant.
+#![cfg_attr(test, allow(warnings))]
+#![cfg_attr(not(test), forbid(clippy::undocumented_unsafe_blocks))]
+#![cfg_attr(
+	not(test),
+	deny(
+		clippy::unwrap_used,
+		clippy::expect_used,
+		clippy::panic,
+		clippy::todo,
+		clippy::unimplemented,
+		clippy::correctness,
+		clippy::option_if_let_else,
+		clippy::or_fun_call,
+		clippy::branches_sharing_code,
+		clippy::single_option_map,
+		clippy::useless_let_if_seq,
+		clippy::redundant_locals,
+		clippy::cloned_ref_to_slice_refs,
+		unsafe_code,
+		clippy::await_holding_lock,
+		clippy::await_holding_refcell_ref,
+		clippy::debug_assert_with_mut_call,
+		clippy::macro_use_imports,
+		clippy::cast_ptr_alignment,
+		clippy::cast_lossless,
+		clippy::ptr_as_ptr,
+		clippy::large_stack_arrays,
+		clippy::same_functions_in_if_condition,
+		trivial_casts,
+		trivial_numeric_casts,
+		unused_extern_crates,
+		unused_import_braces,
+		rust_2018_idioms
+	)
+)]
+#![cfg_attr(
+	not(test),
+	allow(
+		clippy::use_self,
+		clippy::redundant_closure,
+		clippy::too_many_arguments,
+		clippy::doc_markdown,
+		clippy::missing_const_for_fn,
+		clippy::unnecessary_operation,
+		clippy::redundant_pub_crate,
+		clippy::derive_partial_eq_without_eq,
+		clippy::type_complexity,
+		clippy::new_ret_no_self,
+		clippy::cast_possible_truncation,
+		clippy::cast_possible_wrap,
+		clippy::significant_drop_tightening,
+		clippy::significant_drop_in_scrutinee,
+		clippy::float_cmp,
+		clippy::nursery
+	)
+)]
+
 pub mod adaptive_buffers;
 pub mod client;
 pub mod direct_relay;