[CELL-293] drop the financial module from the ultimate stack so CI's arm64 thin build stops stalling on yahoo-finance-mcp's source rebuild

- chore(infra): remove the `financial` import + enable from `nixhome/stacks/ultimate.nix` and from `devcellProfiles.ultimate` in `nixhome/flake.nix`. yahoo-finance-mcp is a custom github derivation (`Alex2Yang97/yahoo-finance-mcp` pinned by rev) that's never cached on `cache.nixos.org`, so every fresh runner rebuilds it from source and the post-install `pythonImportsCheckPhase` stalls CI on arm64. `cell modules list` still shows financial in the catalog and `cell build --modules financial` still works — the module isn't deleted, just removed from the default `ultimate` composition

Author: DimmKirr

nixhome/flake.nix

@@ -115,7 +115,7 @@
         # from fullstack
         "build" "go" "apple" "infra" "node" "project-management" "python" "qa-tools" "scraping"
         # ultimate additions
-        "android" "desktop" "electronics" "financial" "graphics" "news" "nixos"
+        "android" "desktop" "electronics" "graphics" "news" "nixos"
         "postgresql" "publishing" "security" "travel" "plex"
       ];
     };

nixhome/stacks/ultimate.nix

@@ -8,7 +8,9 @@
     ../modules/android.nix
     ../modules/desktop
     ../modules/electronics.nix
-    ../modules/financial.nix
+    # CELL-293: financial temporarily removed from ultimate — yahoo-finance-mcp
+    # rebuilds from source on every fresh runner (custom github derivation, not
+    # on cache.nixos.org) and its pythonImportsCheck stalls CI on arm64.
     ../modules/graphics.nix
     ../modules/llm
     ../modules/media
@@ -27,7 +29,6 @@
   devcell.modules.android.enable = true;
   devcell.modules.desktop.enable = true;
   devcell.modules.electronics.enable = true;
-  devcell.modules.financial.enable = true;
   devcell.modules.graphics.enable = true;
   devcell.modules.news.enable = true;
   devcell.modules.nixos.enable = true;