fix(tui): assert normalized footer paths in spillover tests

8f2b622dc normalized the model-facing artifact footer to forward slashes
(platform-independent). Two unit tests still asserted the raw OS path
against that footer, failing on the Windows lane:

- truncate::adaptive_evidence_footer_names_artifact_path_and_recovery
- subagent::subagent_tool_results_spill_to_disk_and_stay_bounded_inline
  (upstream fa7c4b055)

Assert the normalized form via format_artifact_relative_path, matching
what the footer actually emits.

crates/tui/src/tools/subagent/tests.rs

@@ -13652,7 +13652,7 @@ fn subagent_tool_results_spill_to_disk_and_stay_bounded_inline() {
         assert!(inline.contains("full output at"));
         assert!(inline.contains(crate::tools::truncate::SPILLOVER_RECOVERY_HINT));
         assert!(inline.contains("\n…\n"));
-        assert!(inline.contains(&path.display().to_string()));
+        assert!(inline.contains(&crate::artifacts::format_artifact_relative_path(&path)));
         assert!(!inline.contains("Exact evidence retained"));
         assert!(inline.contains("retrieve_tool_result"), "{inline}");
         // Full output remains recoverable from disk.

crates/tui/src/tools/truncate.rs

@@ -1687,7 +1687,11 @@ mod tests {
             assert!(result.content.contains("of output omitted ("));
             assert!(result.content.contains(" lines)"));
             assert!(result.content.contains("full output at"));
-            assert!(result.content.contains(&path.display().to_string()));
+            assert!(
+                result
+                    .content
+                    .contains(&crate::artifacts::format_artifact_relative_path(&path))
+            );
             assert!(result.content.contains(SPILLOVER_RECOVERY_HINT));
             assert!(!result.content.contains(SPILLOVER_PREVIEW_HINT));