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/base/shell/starship.nix

@@ -0,0 +1,70 @@
+# Starship cross-shell prompt with nix-colors theming.
+{
+  config,
+  lib,
+  ...
+}:
+with lib; let
+  cfg = config.base.shell.starship;
+in {
+  # Enabled by default — base modules are always-on.
+  options.base.shell.starship.enable = (mkEnableOption "enable starship prompt") // {default = true;};
+
+  config = mkIf cfg.enable {
+    programs.starship = {
+      enable = true;
+      enableFishIntegration = true;
+      enableNushellIntegration = true;
+      settings = {
+        format = "$all$character";
+        palette = "universal";
+
+        palettes.universal = {
+          background = "#${config.colorScheme.palette.base00}";
+          surface = "#${config.colorScheme.palette.base01}";
+          muted = "#${config.colorScheme.palette.base03}";
+          text = "#${config.colorScheme.palette.base05}";
+          bright = "#${config.colorScheme.palette.base07}";
+          accent1 = "#${config.colorScheme.palette.base08}";
+          accent2 = "#${config.colorScheme.palette.base09}";
+          accent3 = "#${config.colorScheme.palette.base0A}";
+          accent4 = "#${config.colorScheme.palette.base0B}";
+          accent5 = "#${config.colorScheme.palette.base0C}";
+          accent6 = "#${config.colorScheme.palette.base0D}";
+          accent7 = "#${config.colorScheme.palette.base0E}";
+        };
+
+        character = {
+          success_symbol = "[❯](accent7)";
+          error_symbol = "[❯](accent1)";
+        };
+
+        directory = {
+          style = "accent6";
+          truncation_length = 3;
+          truncate_to_repo = false;
+        };
+
+        git_branch = {
+          style = "accent7";
+        };
+
+        git_status = {
+          style = "accent5";
+        };
+
+        cmd_duration = {
+          style = "accent3";
+        };
+
+        hostname = {
+          style = "accent4";
+        };
+
+        username = {
+          style_user = "accent2";
+        };
+      };
+    };
+  };
+}