Introduce build-time version reference file to make versioning instantaneous and solid

Co-authored-by: arena-agent <297053741+arena-agent@users.noreply.github.com>

app/sovran_systemsos_web/config.py

@@ -1,4 +1,4 @@
-"""Load the Nix-generated config for Sovran_SystemsOS_Hub."""
+"""Load the Nix-generated config and build-time versions for Sovran_SystemsOS_Hub."""
 
 import json
 import os
@@ -18,3 +18,23 @@ def load_config() -> dict:
             return json.load(fh)
     except (FileNotFoundError, json.JSONDecodeError):
         return {"refresh_interval": 5, "command_method": "systemctl", "services": []}
+
+
+def load_versions() -> dict:
+    """Read the Nix-generated or fallback build-time package versions."""
+    path = os.environ.get("SOVRAN_HUB_VERSIONS")
+    if not path:
+        # Candidate 1: parent folder (same as config.json, typical for Nix layout)
+        parent_dir = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+        candidate1 = os.path.join(parent_dir, "versions.json")
+        if os.path.exists(candidate1):
+            path = candidate1
+        else:
+            # Candidate 2: local package folder (dev folder structure)
+            path = os.path.join(os.path.dirname(os.path.abspath(__file__)), "versions.json")
+
+    try:
+        with open(path, "r") as fh:
+            return json.load(fh)
+    except (FileNotFoundError, json.JSONDecodeError):
+        return {}