feat: initial m3ta-home structure

- flake.nix with nixpkgs, home-manager, nix-colors, m3ta-nixpkgs, agenix, NUR inputs
- lib/mkHome.nix: compose HM config from user + identity + context + sets
- profiles/base: shell, cli-tools, secrets (always loaded)
- profiles/contexts/desktop: WM, apps, theme, ghostty
- profiles/contexts/server: minimal headless
- profiles/sets/coding: core (git, direnv, jq, rg), editor, lsp, languages, agents
- profiles/sets/gaming: steam, gamescope, gpu
- profiles/sets/media: obs, ffmpeg, kdenlive, handbrake, yt-dlp
- users/m3tam3re/identities: private.nix, work.nix (git, jj, ssh per identity)
- users/m3tam3re/preferences: cliphist, difftastic, base packages

profiles/contexts/desktop/apps/crypto.nix

@@ -0,0 +1,16 @@
+# Cryptocurrency applications — Bisq, Monero GUI, and Trezor Suite.
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+with lib; let
+  cfg = config.desktop.apps.crypto;
+in {
+  options.desktop.apps.crypto.enable = mkEnableOption "enable crypto applications";
+
+  config = mkIf cfg.enable {
+    home.packages = with pkgs; [bisq2 monero-gui trezor-suite];
+  };
+}

profiles/contexts/desktop/apps/default.nix

@@ -0,0 +1,10 @@
+# Desktop apps aggregator — Obsidian, Office, web apps, crypto tools, and productivity.
+{...}: {
+  imports = [
+    ./obsidian.nix
+    ./office.nix
+    ./webapps.nix
+    ./crypto.nix
+    ./productivity.nix
+  ];
+}

profiles/contexts/desktop/apps/obsidian.nix

@@ -0,0 +1,25 @@
+# Obsidian knowledge base with markdown MIME association.
+{
+  config,
+  lib,
+  ...
+}:
+with lib; let
+  cfg = config.desktop.apps.obsidian;
+in {
+  options.desktop.apps.obsidian.enable = mkEnableOption "enable Obsidian knowledge base";
+
+  config = mkIf cfg.enable {
+    programs.obsidian.enable = true;
+
+    xdg.mimeApps = {
+      enable = true;
+      associations.added = {
+        "text/markdown" = ["obsidian.desktop"];
+      };
+      defaultApplications = {
+        "text/markdown" = ["obsidian.desktop"];
+      };
+    };
+  };
+}

profiles/contexts/desktop/apps/office.nix

@@ -0,0 +1,16 @@
+# Office and productivity applications — LibreOffice and document tools.
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+with lib; let
+  cfg = config.desktop.apps.office;
+in {
+  options.desktop.apps.office.enable = mkEnableOption "install office and paperwork apps";
+
+  config = mkIf cfg.enable {
+    home.packages = [pkgs.libreoffice-fresh];
+  };
+}

profiles/contexts/desktop/apps/productivity.nix

@@ -0,0 +1,18 @@
+# Productivity tools — Pomodoro timer and focus utilities.
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+with lib; let
+  cfg = config.desktop.apps.productivity;
+in {
+  options.desktop.apps.productivity.enable = mkEnableOption "enable productivity tools";
+
+  config = mkIf cfg.enable {
+    home.packages = with pkgs; [
+      pomodoro-timer
+    ];
+  };
+}

profiles/contexts/desktop/apps/webapps.nix

@@ -0,0 +1,56 @@
+# Web application desktop entries — Teams, Outlook, Basecamp, and OpenCode launchers.
+{
+  config,
+  pkgs,
+  ...
+}: let
+  icons = {
+    teams = pkgs.fetchurl {
+      url = "https://cdn.jsdelivr.net/gh/homarr-labs/dashboard-icons/svg/microsoft-teams.svg";
+      sha256 = "sha256-Pr9QS8nnXJq97r4/G3c6JXi34zxHl0ps9gcyI8cN/s8=";
+    };
+    outlook = pkgs.fetchurl {
+      url = "https://cdn.jsdelivr.net/gh/homarr-labs/dashboard-icons/svg/microsoft-outlook.svg";
+      sha256 = "sha256-3u8t5QNHFZvrAegxBiGicO4PjtMWhEaQSCv7MSSfLLc=";
+    };
+    opencode = pkgs.fetchurl {
+      url = "https://cdn.jsdelivr.net/gh/homarr-labs/dashboard-icons/svg/opencode-dark.svg";
+      sha256 = "1lms4f8habamvdh2qqqz9psx4py9wx23mmlkkds44pvrbq3bkj3n";
+    };
+  };
+in {
+  xdg.desktopEntries = {
+    teams = {
+      name = "Microsoft Teams";
+      exec = "launch-webapp https://teams.microsoft.com";
+      comment = "Open Microsoft Teams as a Desktop App";
+      categories = ["Application" "Network" "Chat"];
+      terminal = false;
+      icon = icons.teams;
+    };
+    outlook = {
+      name = "Microsoft Outlook";
+      exec = "launch-webapp https://outlook.office.com/mail/";
+      comment = "Open Microsoft Outlook as a Desktop App";
+      categories = ["Application" "Network"];
+      terminal = false;
+      icon = icons.outlook;
+    };
+    basecamp = {
+      name = "Basecamp";
+      exec = "launch-webapp https://3.basecamp.com/5996442/";
+      comment = "Open Basecamp as a Desktop App";
+      categories = ["Application" "Network"];
+      terminal = false;
+      icon = "${config.home.homeDirectory}/.local/share/icons/basecamp-logo.png";
+    };
+    opencode = {
+      name = "Opencode";
+      exec = "rofi-project-opener";
+      comment = "Open Opencode Terminal App";
+      categories = ["Application" "Development"];
+      terminal = false;
+      icon = icons.opencode;
+    };
+  };
+}