feat(pipeline): refactor into its own project

flake.nix

@@ -4,22 +4,30 @@
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
     flake-utils.url = "github:numtide/flake-utils";
+    pipeline.url = "path:./pipeline";
   };
 
-  outputs = { self, nixpkgs, flake-utils }:
+  outputs = { self, nixpkgs, flake-utils, pipeline }:
     flake-utils.lib.eachDefaultSystem (system:
       let
         pkgs = import nixpkgs { inherit system; };
+        fs = pkgs.lib.fileset;
 
-        # Emacs with ox-hugo — shared between devShell and buildApp
-        emacsWithOxHugo = (pkgs.emacsPackagesFor pkgs.emacs-nox).emacsWithPackages
-          (epkgs: [ epkgs.ox-hugo ]);
+        pipelineApp = pipeline.packages.${system}.default;
 
-        # Pre-fetched npm dependency tree (node_modules)
+        # Pre-fetched npm dependency tree (node_modules).
+        # src is filtered to only package.json + package-lock.json so that
+        # edits to Quartz source files do not invalidate this derivation.
         quartzDeps = pkgs.buildNpmPackage {
           pname = "quartz-deps";
           version = "4.5.2";
-          src = ./.;
+          src = fs.toSource {
+            root = ./.;
+            fileset = fs.unions [
+              ./package.json
+              ./package-lock.json
+            ];
+          };
           npmDepsHash = "sha256-7u+VlIx44B3/ivM9vLMIOn+e4TL4eS6B682vhS+Ikb4=";
           dontBuild = true;
           installPhase = ''
@@ -28,18 +36,10 @@
           '';
         };
 
-        # Pre-fetched Hex/Mix dependencies for scripts/pipeline
-        pipelineMixDeps = pkgs.beamPackages.fetchMixDeps {
-          pname = "pipeline-mix-deps";
-          version = "0.1.0";
-          src = ./scripts/pipeline;
-          sha256 = "sha256-E79X+nUy86G1Jrwv3T7dXekoGv8Hd14ZgJSKWjvlmAw=";
-        };
-
         # The build application wrapper script
         buildApp = pkgs.writeShellApplication {
           name = "build";
-          runtimeInputs = [ pkgs.nodejs_22 pkgs.elixir emacsWithOxHugo ];
+          runtimeInputs = [ pkgs.nodejs_22 ];
           text = ''
             NOTES_DIR="''${1:?Usage: build <path-to-notes-dir>}"
             NOTES_DIR=$(realpath "$NOTES_DIR")
@@ -54,15 +54,10 @@
             # Drop in pre-built node_modules
             ln -s ${quartzDeps}/node_modules "$WORK/repo/node_modules"
 
-            # Drop in pre-fetched Mix deps so mix compile runs offline
-            cp -r ${pipelineMixDeps} "$WORK/repo/scripts/pipeline/deps"
-            chmod -R u+w "$WORK/repo/scripts/pipeline/deps"
-
-            # ox-hugo requires static/ to exist before it can copy image assets
-            mkdir -p "$WORK/repo/static"
-
-            # Run the export pipeline (org → md, citations transform)
-            NOTES_DIR="$NOTES_DIR" elixir "$WORK/repo/scripts/export.exs"
+            # Run the pre-compiled pipeline escript (org → md, citations transform)
+            ${pipelineApp}/bin/pipeline "$NOTES_DIR" \
+              --output "$WORK/repo" \
+              --content-dir "$WORK/repo/content"
 
             # Build the static site from within the repo copy so relative paths
             # (e.g. ./package.json in constants.js) resolve correctly.
@@ -79,19 +74,18 @@
           buildInputs = [
             pkgs.nodejs_22
             pkgs.elixir
-            emacsWithOxHugo
             pkgs.mcp-nixos
           ];
 
           shellHook = ''
             echo "Node $(node --version) / npm $(npm --version)"
             elixir --version 2>/dev/null | head -1 || true
-            echo "Emacs $(emacs --version | head -1)"
           '';
         };
 
         packages.default = buildApp;
         packages.build = buildApp;
+        packages.pipeline = pipelineApp;
 
         apps.default = { type = "app"; program = "${buildApp}/bin/build"; };
         apps.build = { type = "app"; program = "${buildApp}/bin/build"; };