test(build): harden convention diagnostics

Exercise malformed static policy, client module/event/state, confirmation, SSE, delay, throttle, and mixed-event values so build-time diagnostics fail closed across the public declarative surface.

req: diagnostics/004

req: convention/006

req: client_local/011

hemx-build/src/lib.rs

@@ -3156,6 +3156,84 @@ fn main() {{
                 "data-hemx-policy",
                 "latest",
             ),
+            (
+                "empty-client",
+                r#"<button data-hemx-client="">Save</button>"#,
+                "data-hemx-client",
+                "non-empty",
+            ),
+            (
+                "client-module-scheme",
+                r#"<main data-hemx-root="app" data-hemx-client-module="https://example.com/app.js"></main>"#,
+                "data-hemx-client-module",
+                "same-origin",
+            ),
+            (
+                "client-event",
+                r#"<button data-hemx-client="save" data-hemx-client-event="blur">Save</button>"#,
+                "data-hemx-client-event",
+                "runtime-supported",
+            ),
+            (
+                "client-version-zero",
+                r#"<button data-hemx-client="save" data-hemx-client-state-version="0">Save</button>"#,
+                "data-hemx-client-state-version",
+                "positive",
+            ),
+            (
+                "client-version-invalid",
+                r#"<button data-hemx-client="save" data-hemx-client-state-version="one">Save</button>"#,
+                "data-hemx-client-state-version",
+                "positive",
+            ),
+            (
+                "client-policy-invalid",
+                r#"<button data-hemx-client="save" data-hemx-client-policy="queue">Save</button>"#,
+                "data-hemx-client-policy",
+                "latest",
+            ),
+            (
+                "events-mixed",
+                r#"<button data-hemx-handle="save" data-hemx-on="click blur">Save</button>"#,
+                "data-hemx-on",
+                "runtime-supported",
+            ),
+            (
+                "confirm-empty",
+                r#"<button data-hemx-handle="save" data-hemx-confirm=" ">Save</button>"#,
+                "data-hemx-confirm",
+                "non-empty",
+            ),
+            (
+                "sse-empty",
+                r#"<main data-hemx-root="app" data-hemx-sse=" "></main>"#,
+                "data-hemx-sse",
+                "non-empty",
+            ),
+            (
+                "delay-empty",
+                r#"<button data-hemx-handle="save" data-hemx-delay="">Save</button>"#,
+                "data-hemx-delay",
+                "milliseconds",
+            ),
+            (
+                "throttle-invalid",
+                r#"<button data-hemx-handle="save" data-hemx-throttle="ms">Save</button>"#,
+                "data-hemx-throttle",
+                "milliseconds",
+            ),
+            (
+                "duration-suffix-only",
+                r#"<button data-hemx-handle="save" data-hemx-delay="s">Save</button>"#,
+                "data-hemx-delay",
+                "milliseconds",
+            ),
+            (
+                "policy-duplicate-anchor",
+                r#"<button data-hemx-handle="save" data-hemx-policy="newest">Save</button>"#,
+                "data-hemx-policy",
+                "latest",
+            ),
             (
                 "debounce",
                 r#"<button data-hemx-handle="save" data-hemx-debounce="soon">Save</button>"#,