feat(neovim): add Neovim configuration and integrate with home profiles

flake.nix

@@ -21,6 +21,7 @@
       url = "github:gmodena/nix-flatpak/?ref=latest";
     };
     vscode-server.url = "github:nix-community/nixos-vscode-server";
+    nixvim.url = "github:nix-community/nixvim";
     llm-agents.url = "github:numtide/llm-agents.nix";
     nix-vscode-extensions.url = "github:nix-community/nix-vscode-extensions";
     agenix = {
@@ -53,6 +54,7 @@
             home-manager.extraSpecialArgs = { inherit inputs; };
             home-manager.sharedModules = [
               plasma-manager.homeModules.plasma-manager
+              inputs.nixvim.homeModules.nixvim
             ];
             home-manager.users.emmatherock = { osConfig, ... }: {
               imports = [ ./home/emmatherock/core.nix ] ++ osConfig.myHomeProfile.extraPrograms;
@@ -74,6 +76,9 @@
             home-manager.useGlobalPkgs = true;
             home-manager.useUserPackages = true;
             home-manager.extraSpecialArgs = { inherit inputs; };
+            home-manager.sharedModules = [
+              inputs.nixvim.homeModules.nixvim
+            ];
             home-manager.users.emmatherock = { osConfig, ... }: {
               imports = [ ./home/emmatherock/core.nix ] ++ osConfig.myHomeProfile.extraPrograms;
             };

home/emmatherock/neovim.nix

@@ -0,0 +1,203 @@
+# Declarative Neovim config via nixvim. Goal: a real, lean IDE — not a
+# feature-for-feature VSCode clone. Every plugin here earns its place.
+
+{ pkgs, ... }:
+
+{
+  programs.nixvim = {
+    enable = true;
+    defaultEditor = true;
+    vimAlias = true; # `vim` -> nvim, handy when SSH'd into the VPS/homelab
+
+    colorschemes.catppuccin = {
+      enable = true;
+      settings.flavour = "mocha";
+    };
+
+    globals.mapleader = " ";
+
+    opts = {
+      number = true;
+      relativenumber = true;
+      shiftwidth = 2;
+      tabstop = 2;
+      expandtab = true;
+      termguicolors = true;
+      signcolumn = "yes";
+      scrolloff = 8;
+    };
+
+    # --- File explorer ---
+    plugins.neo-tree = {
+      enable = true;
+      settings.window.width = 30;
+    };
+
+    # --- Fuzzy finder: files, grep, buffers, LSP symbols ---
+    plugins.telescope = {
+      enable = true;
+      extensions.fzf-native.enable = true;
+    };
+
+    # --- Treesitter: syntax highlighting/parsing for your stack ---
+    plugins.treesitter = {
+      enable = true;
+      settings.ensure_installed = [
+        "nix" "bash" "lua" "markdown" "json" "yaml"
+        "rust" "go" "gomod" "c" "cpp" "c_sharp" "python"
+        "javascript" "typescript" "tsx" "vue" "html" "css"
+      ];
+    };
+
+    # --- LSP: one server per language/toolchain you use ---
+    plugins.lsp = {
+      enable = true;
+      servers = {
+        nixd.enable = true;
+        bashls.enable = true;
+        rust_analyzer = {
+          enable = true;
+          installCargo = true;
+          installRustc = true;
+        };
+        gopls.enable = true;
+        clangd.enable = true; # C / C++
+        csharp_ls.enable = true;
+        pyright.enable = true;
+        ts_ls.enable = true; # JS/TS, React
+        volar.enable = true; # Vue
+        html.enable = true;
+        cssls.enable = true;
+        tailwindcss.enable = true;
+        jsonls.enable = true;
+      };
+      keymaps.lspBuf = {
+        "gd" = "definition";
+        "gr" = "references";
+        "K" = "hover";
+        "<leader>rn" = "rename";
+        "<leader>ca" = "code_action";
+      };
+    };
+
+    # --- Autocompletion ---
+    plugins.cmp = {
+      enable = true;
+      settings.sources = [
+        { name = "nvim_lsp"; }
+        { name = "path"; }
+        { name = "buffer"; }
+      ];
+    };
+    plugins.cmp-nvim-lsp.enable = true;
+    plugins.cmp-path.enable = true;
+    plugins.cmp-buffer.enable = true;
+
+    # --- Format on save ---
+    plugins.conform-nvim = {
+      enable = true;
+      settings = {
+        format_on_save = {
+          lsp_fallback = true;
+          timeout_ms = 500;
+        };
+        formatters_by_ft = {
+          rust = [ "rustfmt" ];
+          go = [ "gofmt" ];
+          c = [ "clang-format" ];
+          cpp = [ "clang-format" ];
+          python = [ "black" ];
+          javascript = [ "prettier" ];
+          typescript = [ "prettier" ];
+          javascriptreact = [ "prettier" ];
+          typescriptreact = [ "prettier" ];
+          vue = [ "prettier" ];
+          nix = [ "nixpkgs-fmt" ];
+        };
+      };
+    };
+
+    # --- Git: gutter signs, hunk stage/reset, blame ---
+    plugins.gitsigns.enable = true;
+
+    # --- Statusline ---
+    plugins.lualine.enable = true;
+
+    # --- Discoverable keybindings while you're still learning ---
+    plugins.which-key.enable = true;
+
+    # --- AI agent: CodeCompanion, curated natively in nixvim ---
+    # Configured to reuse your existing `claude`/`gemini` CLI auth via ACP
+    # adapters instead of a separate Anthropic Console API key.
+    #
+    # Verified against https://codecompanion.olimorris.dev/configuration/adapters-acp
+    # (CodeCompanion >= v18.0.0, which is what's pinned by nixvim's nixpkgs as of
+    # 2026-08). Two things changed from an older/assumed layout:
+    #   - the default-adapter key is `interactions.chat.adapter`, not
+    #     `strategies.chat.adapter` (renamed in v18.0.0);
+    #   - the built-in adapter names are `claude_code` and `gemini_cli` (no
+    #     `_acp` suffix) and live under `adapters.acp.<name>`.
+    #
+    # Neither adapter has a true zero-config mode that silently piggybacks on
+    # an already-logged-in CLI session:
+    #   - gemini_cli: `defaults.auth_method = "oauth-personal"` reuses the
+    #     `gemini` CLI's own login — no key needed, closest thing to "just
+    #     use my existing session".
+    #   - claude_code: there's no oauth-personal equivalent. Run
+    #     `claude setup-token` once (ties to your Pro/Max subscription rather
+    #     than a Console API key) and save the result to
+    #     ~/.config/codecompanion/claude-oauth-token (chmod 600, outside the
+    #     nix store). It's read at runtime via the `cmd:` prefix below rather
+    #     than embedded in this file.
+    plugins.codecompanion = {
+      enable = true;
+      settings = {
+        interactions.chat.adapter = "claude_code"; # switch to "gemini_cli" per-chat
+        adapters.acp = {
+          claude_code.__raw = ''
+            function()
+              return require("codecompanion.adapters").extend("claude_code", {
+                env = {
+                  CLAUDE_CODE_OAUTH_TOKEN = "cmd:cat ~/.config/codecompanion/claude-oauth-token",
+                },
+              })
+            end
+          '';
+          gemini_cli.__raw = ''
+            function()
+              return require("codecompanion.adapters").extend("gemini_cli", {
+                defaults = {
+                  auth_method = "oauth-personal",
+                },
+              })
+            end
+          '';
+        };
+      };
+    };
+
+    # --- Editor-level tooling only: formatters conform.nvim shells out to.
+    #     Language toolchains themselves (cargo, go, dotnet-sdk, nodejs,
+    #     a compiler, a python interpreter) come from your per-project
+    #     nix-shell / flake devShell, not from here — launch nvim from
+    #     inside that shell (`nix develop`, or nix-shell + direnv) so LSP
+    #     servers resolve the right toolchain via PATH.
+    extraPackages = with pkgs; [
+      python3Packages.black
+      prettier
+      nixpkgs-fmt
+    ];
+
+    keymaps = [
+      { mode = "n"; key = "<leader>e"; action = "<cmd>Neotree toggle<CR>"; }
+      { mode = "n"; key = "<leader>ff"; action = "<cmd>Telescope find_files<CR>"; }
+      { mode = "n"; key = "<leader>fg"; action = "<cmd>Telescope live_grep<CR>"; }
+      { mode = "n"; key = "<leader>fb"; action = "<cmd>Telescope buffers<CR>"; }
+
+      # CodeCompanion
+      { mode = [ "n" "v" ]; key = "<leader>ac"; action = "<cmd>CodeCompanionChat Toggle<CR>"; }
+      { mode = "v"; key = "<leader>aa"; action = "<cmd>CodeCompanionChat Add<CR>"; }
+      { mode = "n"; key = "<leader>ai"; action = "<cmd>CodeCompanion<CR>"; } # inline assistant
+    ];
+  };
+}

hosts/miku-homelab/default.nix

@@ -27,6 +27,7 @@
     ../../home/emmatherock/deskflow.nix
     ../../home/emmatherock/gaming.nix
     ../../home/emmatherock/media.nix
+    ../../home/emmatherock/neovim.nix
     ../../home/emmatherock/packages.nix
     ../../home/emmatherock/plasma.nix
     ../../home/emmatherock/vscode.nix

hosts/vps/default.nix

@@ -13,6 +13,7 @@
 
   myHomeProfile.extraPrograms = [
     ../../home/emmatherock/agents.nix
+    ../../home/emmatherock/neovim.nix
   ];
 
   myNetworking = {