feat(v1): harden typed runtime boundaries

Elect one canonical EffectBatch codec, remove the parallel postcard API, and strengthen fail-closed host, form, sync, WASM, macro, generated-contract, and test-harness proofs with mutation-driven coverage.

req: wire/008

req: wire/009

req: wire/010

req: push/008

req: client_local/015

req: client_local/016

req: client_local/017

req: client_local/018

req: client_local/019

req: sync/024

req: sync/025

req: sync/026

req: sync/027

req: sync/028

req: sync/029

req: test/020

req: test/021

hemx-test/src/lib.rs

@@ -420,10 +420,11 @@ pub fn scoped_island_readout_selector(scope_selector: &str) -> String {
 
 fn assert_simple_selector_part(value: &str, label: &str) {
     assert!(
-        value
-            .chars()
-            .all(|ch| ch.is_ascii_alphanumeric() || ch == '-'),
-        "{label} selector part must contain only ascii alphanumerics or '-'"
+        !value.is_empty()
+            && value
+                .chars()
+                .all(|ch| ch.is_ascii_alphanumeric() || ch == '-'),
+        "{label} selector part must contain one or more ascii alphanumerics or '-'"
     );
 }
 
@@ -437,8 +438,7 @@ fn runtime_resource_attr(kind: ResourceKind) -> &'static str {
 }
 
 fn runtime_attr_marker(name: &str, value: &str) -> String {
-    let escaped = value.replace('"', """);
-    format!(r#"{name}="{escaped}""#)
+    format!(r#"{name}="{value}""#)
 }
 
 fn attr_selector(name: &str, value: &str) -> String {