feat: stage plain project files via the sync namespace (load-path-rework 0001 §4 full, client)

stageViaProjectSync: plain uploaded files (revision>0, not ydoc-backed, not
the target) stage from a one-layer static SyncStack over the backend's
project sync surface — ONE bundle GET cold, a manifest diff warm, bodies
IDB-mirrored like a library. The target keeps its room-materialized wrapper,
ydoc-backed files keep the negotiated per-file fetch, a namespace miss (a
write raced the listing) falls back per-file, and ANY namespace failure
(older backend, decode error) falls back wholesale — exactly the previous
behavior. Demo/local sources pass no config and are untouched.

Measured (Arduino repo-as-project, 108 files = 76 plain + 32 ydoc-backed):
cold 76 requests → 1 bundle; warm 1 manifest GET, 0 bodies.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VLSht9cadprtT2mhynawWu

web/standalone/src/components/WasmTool.tsx

@@ -1887,6 +1887,18 @@ export function WasmTool({
               ? (relPath) =>
                   relPath === targetPath ? Promise.resolve(targetBytes) : fetchBytes(relPath)
               : fetchBytes,
+          // Plain files stage via the project sync namespace — one bundle GET
+          // cold, a manifest diff warm (0001 §4 full). Backend projects only:
+          // the gallery/local sources have no sync routes and no CAS rows.
+          projectSync:
+            sourceDescriptor?.kind === "remote-rw" && scopeId !== "local"
+              ? {
+                  apiBase: API_BASE_URL,
+                  scope: currentScope(),
+                  scopeId,
+                  projectId,
+                }
+              : null,
           log: append,
           onStatus: setStatus,
           onFileProgress: (done, total) =>

web/standalone/src/wasm/kicad-runner.ts

@@ -1,5 +1,6 @@
 import type { Tool } from "@pcbjam/shared";
 import { FILELESS_TOOLS, toolForFile } from "@pcbjam/shared";
+import { SyncStack } from "@pcbjam/sync-client";
 import { defaultKicadPro } from "../lib/new-file";
 import { memfsFilePath, memfsProjectDir } from "./constants";
 import { mark } from "./load-trace";
@@ -9,10 +10,32 @@ import { openFileInTool } from "./open-flow";
 /**
  * The only thing the editor needs to know about a file to sync it into MEMFS:
  * its project-relative POSIX path. Both the contract loader (whose ProjectFile
- * is a superset of this) and the local-folder loader satisfy it.
+ * is a superset of this) and the local-folder loader satisfy it. The optional
+ * fields are the contract loader's collab/CAS overlay — when present they let
+ * staging route the file through the project sync namespace (plain uploaded
+ * files) vs the per-file negotiated fetch (ydoc-backed files).
  */
 export interface ToolFile {
   path: string;
+  revision?: number;
+  hasYdoc?: boolean;
+  isLive?: boolean;
+}
+
+/**
+ * The project-as-sync-namespace endpoints (load-path-rework 0001 §4 full):
+ * plain files stage through ONE bundle GET cold / a manifest diff warm,
+ * IDB-mirrored like a library. Absent (demo gallery, local folders, older
+ * backends) ⇒ every file takes the per-file path, exactly as before.
+ */
+export interface ProjectSyncConfig {
+  apiBase: string;
+  scope: string;
+  scopeId: string;
+  projectId: string;
+  /** Test seams (default: credentialed global fetch / IndexedDB stores). */
+  fetchImpl?: typeof fetch;
+  storeFactory?: ConstructorParameters<typeof SyncStack>[0]["storeFactory"];
 }
 
 export interface DriveOptions {
@@ -21,6 +44,7 @@ export interface DriveOptions {
   files: ToolFile[];
   targetPath?: string;
   fetchBytes: (relPath: string) => Promise<Uint8Array>;
+  projectSync?: ProjectSyncConfig | null;
   log: (msg: string) => void;
   onStatus: (text: string) => void;
   /** Per-file staging progress (files fetched+written so far, total) — drives
@@ -122,34 +146,113 @@ async function syncProjectToMemfs(win: ToolWindow, opts: DriveOptions): Promise<
 
   let staged = 0;
   opts.onFileProgress?.(0, opts.files.length);
-  const queue = [...opts.files];
+  const stageOne = (path: string, bytes: Uint8Array): void => {
+    restageFile(win, opts.slug, path, bytes, opts.log);
+    opts.onFileProgress?.(++staged, opts.files.length);
+    // 3D models: prefetch every model this board references (R2 → IDB → MEMFS)
+    // so the 3D viewer's first open resolves locally. Fire-and-forget — project
+    // open never waits on it; a ref that misses falls back to the C++ per-model
+    // ensure. No-op unless a model source is installed (bootKicadTool).
+    if (path.endsWith(".kicad_pcb")) {
+      const text = new TextDecoder().decode(bytes);
+      void prescanBoardModels(text).catch((e) =>
+        opts.log(`[3d] prescan failed: ${String(e)}`),
+      );
+    }
+  };
+
+  // Plain uploaded files stage through the project sync namespace when the
+  // backend offers one — one bundle GET cold, a manifest diff warm — and any
+  // file the namespace cannot vouch for falls back to the per-file path:
+  // ydoc-backed files (their bytes ride room materialization), the TARGET
+  // (its bytes may come from the connected doc room via the fetchBytes
+  // wrapper), and everything on any namespace failure at all.
+  const perFile = await (opts.projectSync
+    ? stageViaProjectSync(opts, stageOne)
+    : Promise.resolve(opts.files));
+
+  const queue = [...perFile];
   const worker = async (): Promise<void> => {
     for (let file = queue.shift(); file; file = queue.shift()) {
       const bytes = await opts.fetchBytes(file.path);
-      restageFile(win, opts.slug, file.path, bytes, opts.log);
-      opts.onFileProgress?.(++staged, opts.files.length);
-      // 3D models: prefetch every model this board references (R2 → IDB → MEMFS)
-      // so the 3D viewer's first open resolves locally. Fire-and-forget — project
-      // open never waits on it; a ref that misses falls back to the C++ per-model
-      // ensure. No-op unless a model source is installed (bootKicadTool).
-      if (file.path.endsWith(".kicad_pcb")) {
-        const text = new TextDecoder().decode(bytes);
-        void prescanBoardModels(text).catch((e) =>
-          opts.log(`[3d] prescan failed: ${String(e)}`),
-        );
-      }
+      stageOne(file.path, bytes);
     }
   };
   // One rejection fails the stage (same as the serial loop did), but let the
   // in-flight siblings settle first so a failure can't leave a fetch writing
   // into MEMFS after the caller has moved on.
   const results = await Promise.allSettled(
-    Array.from({ length: Math.min(STAGE_CONCURRENCY, opts.files.length) }, worker),
+    Array.from({ length: Math.min(STAGE_CONCURRENCY, queue.length) }, worker),
   );
   const failed = results.find((r) => r.status === "rejected");
   if (failed) throw (failed as PromiseRejectedResult).reason;
 }
 
+/**
+ * Stage every namespace-eligible file from the project sync stack, returning
+ * the files that still need the per-file path. Exported for tests.
+ */
+export async function stageViaProjectSync(
+  opts: Pick<DriveOptions, "slug" | "files" | "targetPath" | "log"> & {
+    projectSync?: ProjectSyncConfig | null;
+  },
+  stageOne: (path: string, bytes: Uint8Array) => void,
+): Promise<ToolFile[]> {
+  const sync = opts.projectSync;
+  if (!sync) return opts.files;
+  const eligible = opts.files.filter(
+    (f) =>
+      f.path !== opts.targetPath &&
+      !f.hasYdoc &&
+      !f.isLive &&
+      (f.revision ?? 0) > 0,
+  );
+  const rest = opts.files.filter((f) => !eligible.includes(f));
+  if (eligible.length === 0) return rest;
+
+  const baseFetch = sync.fetchImpl ?? fetch;
+  const credentialed: typeof fetch = (input, init) =>
+    baseFetch(input, { ...init, credentials: "include" });
+  const stack = new SyncStack({
+    layers: [
+      {
+        // Ids (stable) key the IDB cache; slugs (renameable) only address HTTP.
+        namespace: `project:${sync.scopeId}:${sync.projectId}`,
+        kind: "static",
+        url: `${sync.apiBase}/api/scopes/${encodeURIComponent(sync.scope)}/projects/${encodeURIComponent(opts.slug)}/sync`,
+      },
+    ],
+    fetchImpl: credentialed,
+    storeFactory: sync.storeFactory,
+  });
+  try {
+    await stack.open();
+    const all = await stack.readAll();
+    const missed: ToolFile[] = [];
+    for (const f of eligible) {
+      const bytes = all.get(f.path);
+      // The namespace manifest raced the project listing (file changed to
+      // ydoc-backed, or was just deleted/renamed): let the per-file path
+      // answer authoritatively.
+      if (!bytes) missed.push(f);
+      else stageOne(f.path, bytes);
+    }
+    if (missed.length) {
+      opts.log(
+        `[stage] ${missed.length} file(s) missed the sync namespace — per-file fallback`,
+      );
+    }
+    return [...rest, ...missed];
+  } catch (e) {
+    // Older backend (no sync routes), quota, decode failure — the whole set
+    // falls back to per-file staging, which is exactly the previous behavior.
+    opts.log(`[stage] project sync namespace unavailable (${String(e)}) — per-file staging`);
+    return opts.files;
+  } finally {
+    stack.close();
+  }
+}
+
 /**
  * KiCad expects a `<stem>.kicad_pro` next to a board/schematic; without one it
  * runs on an in-memory defaults project, so nothing project-scoped (netclasses,

web/standalone/src/wasm/project-stage-sync.test.ts

@@ -0,0 +1,131 @@
+import { describe, expect, it } from "vitest";
+import { encodeBundle, type SyncManifest } from "@pcbjam/shared";
+import { memStore } from "@pcbjam/sync-client";
+import {
+  stageViaProjectSync,
+  type ProjectSyncConfig,
+  type ToolFile,
+} from "./kicad-runner";
+
+/**
+ * Plain files stage from the project sync namespace (one bundle GET cold);
+ * ydoc-backed files, the target, and anything the namespace can't vouch for
+ * stay on the per-file path — and ANY namespace failure falls back wholesale
+ * (older backend without the routes = exactly the previous behavior).
+ */
+
+const enc = new TextEncoder();
+
+function fakeSyncServer(bodies: Record<string, string>) {
+  const manifest: SyncManifest = { version: 1, entries: {} };
+  const frames: Array<[string, Uint8Array]> = [];
+  for (const [path, text] of Object.entries(bodies)) {
+    const b = enc.encode(text);
+    manifest.entries[path] = { hash: `r1:u${b.length}`, size: b.length, mtime: 0 };
+    frames.push([path, b]);
+  }
+  let bundleFetches = 0;
+  const fetchImpl = (async (input: unknown) => {
+    const url = String(input);
+    if (url.endsWith("/sync/manifest")) return Response.json(manifest);
+    if (url.endsWith("/sync/bundle")) {
+      bundleFetches += 1;
+      return new Response(encodeBundle(manifest, frames) as BodyInit);
+    }
+    return new Response(null, { status: 404 });
+  }) as typeof fetch;
+  return { fetchImpl, counters: { get bundleFetches() { return bundleFetches; } } };
+}
+
+function syncConfig(fetchImpl: typeof fetch): ProjectSyncConfig {
+  const stores = new Map<string, ReturnType<typeof memStore>>();
+  return {
+    apiBase: "https://api.test",
+    scope: "team",
+    scopeId: "scope-1",
+    projectId: "proj-1",
+    fetchImpl,
+    storeFactory: (ns) => stores.get(ns) ?? stores.set(ns, memStore()).get(ns)!,
+  };
+}
+
+describe("stageViaProjectSync", () => {
+  it("stages plain files from ONE bundle; special files stay per-file", async () => {
+    const server = fakeSyncServer({
+      "a.kicad_pcb": "(pcb)",
+      "docs/readme.md": "hi",
+    });
+    const files: ToolFile[] = [
+      { path: "a.kicad_pcb", revision: 1 },
+      { path: "docs/readme.md", revision: 1 },
+      { path: "root.kicad_sch", revision: 3, hasYdoc: true },
+      { path: "live.kicad_sch", revision: 2, isLive: true },
+      { path: "subsheet.kicad_sch", revision: 0 },
+      { path: "target.kicad_pcb", revision: 5 },
+    ];
+    const stagedPaths: string[] = [];
+    const rest = await stageViaProjectSync(
+      {
+        slug: "proj",
+        files,
+        targetPath: "target.kicad_pcb",
+        projectSync: syncConfig(server.fetchImpl),
+        log: () => {},
+      },
+      (path, bytes) => stagedPaths.push(`${path}:${bytes.length}`),
+    );
+
+    expect(stagedPaths.sort()).toEqual(["a.kicad_pcb:5", "docs/readme.md:2"]);
+    expect(server.counters.bundleFetches).toBe(1);
+    expect(rest.map((f) => f.path).sort()).toEqual([
+      "live.kicad_sch",
+      "root.kicad_sch",
+      "subsheet.kicad_sch",
+      "target.kicad_pcb",
+    ]);
+  });
+
+  it("a file the namespace manifest missed falls back to per-file", async () => {
+    // The listing knows b.txt, the namespace snapshot doesn't (raced write,
+    // just-turned-ydoc): the per-file path must answer authoritatively.
+    const server = fakeSyncServer({ "a.txt": "A" });
+    const files: ToolFile[] = [
+      { path: "a.txt", revision: 1 },
+      { path: "b.txt", revision: 1 },
+    ];
+    const staged: string[] = [];
+    const rest = await stageViaProjectSync(
+      { slug: "p", files, projectSync: syncConfig(server.fetchImpl), log: () => {} },
+      (path) => staged.push(path),
+    );
+    expect(staged).toEqual(["a.txt"]);
+    expect(rest.map((f) => f.path)).toEqual(["b.txt"]);
+  });
+
+  it("any namespace failure falls back WHOLESALE to per-file staging", async () => {
+    const fetchImpl = (async () =>
+      new Response(null, { status: 404 })) as typeof fetch; // older backend
+    const files: ToolFile[] = [
+      { path: "a.txt", revision: 1 },
+      { path: "b.txt", revision: 1 },
+    ];
+    const staged: string[] = [];
+    const rest = await stageViaProjectSync(
+      { slug: "p", files, projectSync: syncConfig(fetchImpl), log: () => {} },
+      (path) => staged.push(path),
+    );
+    expect(staged).toEqual([]);
+    expect(rest).toEqual(files);
+  });
+
+  it("no sync config means the whole set is per-file (demo/local sources)", async () => {
+    const files: ToolFile[] = [{ path: "a.txt", revision: 1 }];
+    const rest = await stageViaProjectSync(
+      { slug: "p", files, projectSync: null, log: () => {} },
+      () => {
+        throw new Error("must not stage");
+      },
+    );
+    expect(rest).toEqual(files);
+  });
+});