fix(deploy): redirect the bare legacy root too (/* splat misses the empty case)

Add an explicit /human-experience-simulator/ → /human-machine-strata/ 301 (the
subpath splat doesn't match the trailing-slash root).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tests/test_build_static.py

@@ -29,6 +29,7 @@ def test_build_emits_frontend_baked_json_and_only_referenced_media(tmp_path):
     redirects = (out / "_redirects").read_text()
     assert "/  /human-machine-strata/  308" in redirects
     assert "/human-machine-strata  /human-machine-strata/  308" in redirects
+    assert "/human-experience-simulator/  /human-machine-strata/  301" in redirects
     assert "/human-experience-simulator/*  /human-machine-strata/:splat  301" in redirects
 
     # baked JSON matches the API shape

tools/build_static.py

@@ -73,6 +73,10 @@ def _write_redirects(out: Path, seg: str) -> None:
         f"/{seg}  /{seg}/  308\n",
     ]
     if LEGACY_APP_PATH and LEGACY_APP_PATH != seg:
+        # Exact root (trailing slash) first — the `/*` splat does NOT match the empty
+        # case, so the bare /legacy/ needs its own rule. Then the splat for subpaths,
+        # then the no-trailing-slash form.
+        lines.append(f"/{LEGACY_APP_PATH}/  /{seg}/  301\n")
         lines.append(f"/{LEGACY_APP_PATH}/*  /{seg}/:splat  301\n")
         lines.append(f"/{LEGACY_APP_PATH}  /{seg}/  301\n")
     (out / "_redirects").write_text("".join(lines))