fix(dashboard): make .env sensitive-file guard case-insensitive

Follow-up to #57507: .ENV / .Env.local on case-insensitive filesystem
mounts slipped past the guard. Lowercase the name before matching and
add a regression test. Addresses egilewski's open review note.

hermes_cli/web_server.py

@@ -1192,8 +1192,13 @@ _FS_READDIR_HIDDEN = {
 # and exposing them through the dashboard file browser is a security leak —
 # see issue #57505.
 def _is_sensitive_filename(name: str) -> bool:
-    """Return True for ``.env`` and any ``.env.<suffix>`` variant."""
-    return name == ".env" or name.startswith(".env.")
+    """Return True for ``.env`` and any ``.env.<suffix>`` variant.
+
+    Case-insensitive so ``.ENV`` / ``.Env.local`` on case-insensitive
+    filesystems (macOS/Windows mounts) can't slip past the guard.
+    """
+    lowered = name.lower()
+    return lowered == ".env" or lowered.startswith(".env.")
 _FS_DATA_URL_MAX_BYTES = 16 * 1024 * 1024
 _FS_TEXT_SOURCE_MAX_BYTES = 64 * 1024 * 1024
 _FS_TEXT_PREVIEW_MAX_BYTES = 512 * 1024

tests/hermes_cli/test_web_server_files.py

@@ -548,3 +548,15 @@ def test_sensitive_env_suffix_variants_blocked(forced_files_client):
         p.write_text(f"SECRET_{suffix}=abc123")
         assert client.get("/api/files/read", params={"path": str(p)}).status_code == 403
         assert client.get("/api/files/download", params={"path": str(p)}).status_code == 403
+
+
+def test_sensitive_env_case_insensitive_blocked(forced_files_client):
+    """Regression: .ENV / .Env.local casings must be blocked too (case-insensitive FS mounts)."""
+    client, root = forced_files_client
+
+    root.mkdir(parents=True, exist_ok=True)
+    for name in (".ENV", ".Env.local", ".eNv.PROD"):
+        p = root / name
+        p.write_text("SECRET=abc123")
+        assert client.get("/api/files/read", params={"path": str(p)}).status_code == 403
+        assert client.get("/api/files/download", params={"path": str(p)}).status_code == 403