Add Obsidian support and update Helium to 0.13.4.1

Introduce a new home module for Obsidian with enable option and BoM
vault.
Expose Obsidian configuration in host‑specific home‑modules files.
Add Stylix theming support for Obsidian (colors, fonts, polarity,
vaults).
Upgrade Helium AppImage to version 0.13.4.1 and update its hash.

hosts/Garand-Desktop/home-modules.nix

@@ -52,6 +52,16 @@ _: {
   */
   anki.enable = true; # Anki: spaced‑repetition flashcard program
 
+  /*
+  Productivity / Knowledge Management
+  */
+  obsidian = {
+    enable = true; # Obsidian: Powerful knowledge base that works on top of a local folder of plain text Markdown files
+    vaults = {
+      "BoM".enable = true; # Blood of Mages: ttrpg session
+    };
+  };
+
   /*
   XDG desktop entries (PWA)
   */

hosts/Garand-Laptop/home-modules.nix

@@ -52,6 +52,16 @@ _: {
   */
   anki.enable = true; # Anki: spaced‑repetition flashcard program
 
+  /*
+  Productivity / Knowledge Management
+  */
+  obsidian = {
+    enable = true; # Obsidian: Powerful knowledge base that works on top of a local folder of plain text Markdown files
+    vaults = {
+      "BoM".enable = true; # Blood of Mages: ttrpg session
+    };
+  };
+
   /*
   XDG desktop entries (PWA)
   */

hosts/default/home-modules.nix

@@ -52,6 +52,16 @@ _: {
   */
   anki.enable = false; # Anki: spaced‑repetition flashcard program
 
+  /*
+  Productivity / Knowledge Management
+  */
+  obsidian = {
+    enable = false; # Obsidian: Powerful knowledge base that works on top of a local folder of plain text Markdown files
+    vaults = {
+      "BoM".enable = false; # Blood of Mages: ttrpg session
+    };
+  };
+
   /*
   XDG desktop entries (PWA)
   */

modules/core/packages/appimages/helium.nix

@@ -4,8 +4,8 @@
   fetchurl,
 }: let
   pname = "helium";
-  version = "0.13.3.1";
-  hash = "sha256-RS+Sn42V+HjCw41N1zayMVIqlgH+i2B2IdVJwBPmw00=";
+  version = "0.13.4.1";
+  hash = "sha256-z23up+T6bj6F+cQslmI92bEksIAw1OQHRIrmQSaaxY8=";
 
   src = fetchurl {
     url = "https://github.com/imputnet/helium-linux/releases/download/${version}/helium-${version}-x86_64.AppImage";

modules/home/default.nix

@@ -8,6 +8,7 @@ _: {
     ./kitty
     ./librewolf
     ./noctalia
+    ./obsidian
     ./scripts
     ./vscodium
     ./xdg

modules/home/obsidian/default-settings/default.nix

@@ -0,0 +1 @@
+_: {}

modules/home/obsidian/default.nix

@@ -0,0 +1,19 @@
+{
+  pkgs,
+  lib,
+  config,
+  ...
+}: {
+  options.obsidian.enable = lib.mkEnableOption "Obsidian";
+
+  config.programs.obsidian = lib.mkIf config.obsidian.enable {
+    enable = true;
+    package = pkgs.obsidian;
+    cli.enable = true;
+  };
+
+  imports = [
+    # ./default-settings
+    ./vaults
+  ];
+}

modules/home/obsidian/vaults/BoM.nix

@@ -0,0 +1,12 @@
+{
+  lib,
+  config,
+  ...
+}: {
+  options.obsidian.vaults."BoM".enable = lib.mkEnableOption "Obsidian BoM vault";
+
+  config.programs.obsidian.vaults."BoM" = lib.mkIf config.obsidian.vaults."BoM".enable {
+    enable = true;
+    target = "Obsidian/BoM";
+  };
+}

modules/home/obsidian/vaults/default.nix

@@ -0,0 +1,5 @@
+_: {
+  imports = [
+    ./BoM.nix
+  ];
+}

modules/home/stylix.nix

@@ -91,5 +91,15 @@
       enable = true;
       colors.enable = true;
     };
+
+    obsidian = {
+      enable = true;
+      colors.enable = true;
+      fonts.enable = true;
+      polarity.enable = true;
+      vaultNames = [
+        "BoM"
+      ];
+    };
   };
 }