fix: hash root password instead of storing in clear text (CWE-312)

- Replace plain-text write of new_root_password in api_security_reset()
  with scrypt-hashed storage via _hash_password(), matching how the free
  password is already handled.

- Return new_root_password in the API response so the user sees it once
  before it is irreversibly hashed on disk.

- Teach _resolve_credential() to detect scrypt hashes and display a
  human-readable placeholder instead of raw hex in the Hub credentials UI.

- Harden root-password-setup systemd service: if the secrets file already
  contains a hash, skip chpasswd so a manual restart never sets the hash
  as the literal login password.

app/sovran_systemsos_web/server.py

@@ -1554,7 +1554,11 @@ def _resolve_credential(cred: dict) -> dict | None:
         else:
             return None
 
-    value = prefix + raw + suffix
+    # Detect scrypt hash (salt_hex:hash_hex) — passwords stored securely
+    if re.match(r'^[0-9a-f]{32}:[0-9a-f]{64,}$', raw):
+        value = "(stored securely — use Security Reset to set a new one)"
+    else:
+        value = prefix + raw + suffix
     result = {"label": label, "value": value, "multiline": multiline}
 
     if qrcode:
@@ -5173,7 +5177,7 @@ async def api_security_reset():
     try:
         os.makedirs("/var/lib/secrets", exist_ok=True)
         with open("/var/lib/secrets/root-password", "w") as f:
-            f.write(new_root_password)
+            f.write(_hash_password(new_root_password))
         os.chmod("/var/lib/secrets/root-password", 0o600)
     except Exception as exc:
         errors.append(f"write root-password: {exc}")
@@ -5195,7 +5199,7 @@ async def api_security_reset():
     except OSError:
         pass  # Non-fatal
 
-    return {"ok": True, "new_password": new_free_password, "errors": errors}
+    return {"ok": True, "new_password": new_free_password, "new_root_password": new_root_password, "errors": errors}
 
 
 @app.post("/api/security/verify-integrity")

modules/credentials.nix

@@ -111,7 +111,15 @@ in
         echo "$ROOT_PASS" > "$SECRET_FILE"
         chmod 600 "$SECRET_FILE"
       fi
-      echo "root:$(cat "$SECRET_FILE")" | chpasswd
+      # If the file contains a scrypt hash (salt:hash), skip chpasswd — the
+      # password was already set via the Hub security reset endpoint and this
+      # service is only re-running as a manual recovery step.
+      CONTENT="$(cat "$SECRET_FILE")"
+      if echo "$CONTENT" | grep -qE '^[0-9a-f]{32}:[0-9a-f]{64,}$'; then
+        echo "root-password-setup: stored value is already hashed — skipping chpasswd" >&2
+      else
+        echo "root:$CONTENT" | chpasswd
+      fi
     '';
   };