Initial roast planner webapp: fillable worksheet, live ledger, curve, URL prefill, .alog reference curve

- shared/ ports the worksheet's ledger math, time parsing, and reference tables
  (cultivars/processes/roast-levels/machine bands) as browser-safe ESM, imported
  by both the server and the browser so the arithmetic can't drift between them.
- server/prefill.js runs a zero-tool Pi Coding Agent SDK turn to extract page facts
  from a bean product URL, then derives worksheet field IDs deterministically from
  reference-data.js — the model never invents a first-crack anchor or a modifier.
- server/alog.js ports the Python alog_parser.py's format handling, including the
  tokenizer-based Python-dict-literal-to-JSON conversion the real files need.
- public/ is the worksheet reproduced as a live HTML form: worksheet.css is a
  verbatim copy of the paper worksheet's print CSS, print.js bakes values into
  the print layout so the same DOM renders both on screen and on paper.
- Ledger math verified against both of the paper worksheet's worked examples;
  alog parser verified against all 14 real logs in ref/roasts/.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

server/index.js

@@ -0,0 +1,77 @@
+import express from "express";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import { fetchPageText } from "./fetch-page.js";
+import { runPrefill } from "./prefill.js";
+import { parseAlog } from "./alog.js";
+import { listAlogLibrary, readAlogFromLibrary } from "./alog-library.js";
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+const ROOT = path.join(__dirname, "..");
+const PORT = Number(process.env.PORT) || 8090;
+
+const app = express();
+app.use(express.json({ limit: "2mb" }));
+
+app.use(express.static(path.join(ROOT, "public")));
+app.use("/shared", express.static(path.join(ROOT, "shared")));
+
+app.post("/api/prefill", async (req, res) => {
+  const url = typeof req.body?.url === "string" ? req.body.url.trim() : "";
+  if (!url) return res.status(400).json({ ok: false, code: "bad_url", error: "Missing url." });
+
+  let page;
+  try {
+    page = await fetchPageText(url);
+  } catch (err) {
+    const code = err.code ?? "fetch_failed";
+    const status = code === "fetch_timeout" ? 504 : code === "bad_url" ? 400 : 502;
+    return res.status(status).json({ ok: false, code, error: err.message });
+  }
+
+  try {
+    const result = await runPrefill(page);
+    res.json({ ok: true, ...result });
+  } catch (err) {
+    console.error("prefill failed:", err);
+    const code = err.code ?? "prefill_failed";
+    const status = code === "no_model" ? 503 : code === "unparseable_model_output" ? 422 : 500;
+    res.status(status).json({ ok: false, code, error: err.message });
+  }
+});
+
+app.post("/api/alog", (req, res) => {
+  const content = req.body?.content;
+  if (typeof content !== "string" || content.trim() === "") {
+    return res.status(400).json({ ok: false, code: "bad_request", error: "Missing .alog file content." });
+  }
+  try {
+    const result = parseAlog(content, req.body?.filename ?? "upload.alog");
+    res.json({ ok: true, ...result });
+  } catch (err) {
+    console.error("alog parse failed:", err);
+    res.status(422).json({ ok: false, code: "unparseable_alog", error: err.message });
+  }
+});
+
+app.get("/api/alog/library", async (_req, res) => {
+  try {
+    res.json({ ok: true, files: await listAlogLibrary() });
+  } catch (err) {
+    res.status(500).json({ ok: false, code: "library_failed", error: err.message });
+  }
+});
+
+app.get("/api/alog/library/:filename", async (req, res) => {
+  try {
+    const result = await readAlogFromLibrary(req.params.filename);
+    res.json({ ok: true, ...result });
+  } catch (err) {
+    const status = err.code === "not_found" ? 404 : err.code === "bad_filename" ? 400 : 422;
+    res.status(status).json({ ok: false, code: err.code ?? "library_read_failed", error: err.message });
+  }
+});
+
+app.listen(PORT, () => {
+  console.log(`Roast planner webapp listening on http://localhost:${PORT}`);
+});