feat(files): @shade/files 0.3.0 — E2EE filesystem RPC primitive

M-Files-1..6 land the full files-RPC layer + everything 0.3.0 needs to
ship. Apps keep their own UI; this layer ships the typed RPC, the
streams bridge for content I/O, and production hooks (rate limit,
retention, fingerprint gate, metrics).

@shade/files (NEW)
- Standard ops: list/stat/mkdir/delete/move/read/write/getThumbnail with
  Zod-validated wire schemas + clean user-handler types.
- Custom ops: typed via TypeScript declaration merging on CustomOpsMap
  + per-op Zod schemas; client.custom('app.foo', {...}) is fully typed.
- Content I/O: inline (≤ 256 KiB plaintext) base64-in-RPC; streams
  (> 256 KiB) ride @shade/transfer via userMetadata.shadeFilesWriteId
  / shadeFilesReadStreamId correlation. Server-side TransformStream
  bridges accept inbound transfers immediately (engine rejects chunks
  that arrive before accept) and park the readable for the matching
  RPC.
- Directory ops: walk(path, opts) async-iterable depth-first walker;
  uploadDirectory()/downloadDirectory() with bounded concurrency pool
  (default 4, cap 16), aggregated progress, abort.
- Production hooks (callback-based, vendor-neutral): rate-limit (op +
  byte), idempotency cache (LRU + TTL + in-flight de-dupe), path
  policy (traversal + percent-decode hardening), fingerprint gate
  (required/optional/reject), pluggable Ed25519 sig verification with
  ±5 min replay window, onMetric sink (standard names).
- React hooks (subpath @shade/files/react): ShadeFilesProvider,
  useShadeFiles, useFileList, useFileTransfer/Upload/Download.
- Shade.files.serve(handler) + Shade.files.client(peer) high-level
  entrypoint in @shade/sdk; lazy + memoized; one handler per Shade.

Wire format bump
- @shade/proto wire VERSION 0x01 → 0x02. Length prefixes changed from
  u16 to u32. The previous u16 silently truncated payloads above
  64 KiB — a hard correctness ceiling that blocked inline file ops
  up to 256 KiB. Wire-incompatible with 0.2.x peers; new sessions
  only. Cross-platform Kotlin port (android/shade-android) updated to
  match; test-vectors/wire-format.json regenerated.

Concurrency safety
- ShadeSessionManager.encrypt/.decrypt now run under per-peer mutex.
  Concurrent decryptions of the same peer raced ratchet state
  (manifested as sporadic "Failed to decrypt — wrong key or tampered
  data" under load — surfaced once concurrent uploadDirectory pumped
  many writes in flight). Encrypt was already serialized via
  Shade.send's encryptChains; decrypt is now serialized at the
  manager layer too.

@shade/streams extension
- StreamMetadata.userMetadata?: Record<string, string> for
  application-level key/value pairs that round-trip verbatim through
  stream-init plaintext. Used by @shade/files for write/read
  correlation; available to any consumer.

@shade/sdk extension
- Shade.files getter (lazy + memoized).
- BackgroundHooks.onPruneFiles + periodic timer (default 5 min) +
  BackgroundTasks.setHook(name, fn) for runtime hook registration.

Bundles in-flight 0.2.0 work
- packages/shade-streams/, packages/shade-transfer/, related
  shade-sdk streams-bridge + shade-widgets transfer hooks were
  uncommitted prior to this session. Including them keeps the
  workspace consistent at 0.3.0 since @shade/files depends on them.

Tests
- 74 new tests in @shade/files (572 → 646 workspace pass; 0 fail;
  3× stable). Coverage spans unit (inline-threshold + concurrency),
  integration (read-write inline + streams up to 1 MiB, walk +
  upload/download directory, custom-op, metrics, SDK namespace
  end-to-end), and security (tampered-envelope sig verification,
  replay window, fingerprint gate, rate-limit + quota).

Release artifacts
- All packages bumped to 0.3.0 via scripts/bump-version.ts.
- scripts/publish-all.ts PACKAGES updated with shade-files in
  topological order (after shade-transfer, before shade-sdk).
- bun run publish:dry clean (14 packed, 0 failed).
- examples/08-files-browser/ — three-process CLI demo (prekey + Bob
  server + Alice CLI) covering list/stat/mkdir/delete/upload/download.
- docs/files.md — full API + design doc.
- CHANGELOG.md 0.3.0 entry.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/shade-streams/tests/sender-receiver.test.ts

@@ -0,0 +1,176 @@
+import { describe, test, expect } from 'bun:test';
+import { SubtleCryptoProvider } from '@shade/crypto-web';
+import {
+  StreamSender,
+  StreamReceiver,
+  StreamFinishedError,
+  generateStreamId,
+  generateStreamSecret,
+} from '../src/index.js';
+
+const crypto = new SubtleCryptoProvider();
+
+function hex(b: Uint8Array): string {
+  return Array.from(b, (x) => x.toString(16).padStart(2, '0')).join('');
+}
+
+async function makePair(opts?: { laneId?: number; startSeq?: number }) {
+  const streamId = generateStreamId(crypto);
+  const streamSecret = generateStreamSecret(crypto);
+  const laneId = opts?.laneId ?? 0;
+  const sender = await StreamSender.create({
+    crypto,
+    streamId,
+    streamSecret,
+    laneId,
+    ...(opts?.startSeq !== undefined ? { startSeq: opts.startSeq } : {}),
+  });
+  const receiver = await StreamReceiver.create({
+    crypto,
+    streamId,
+    streamSecret,
+    laneId,
+    ...(opts?.startSeq !== undefined ? { startSeq: opts.startSeq } : {}),
+  });
+  return { sender, receiver, streamId, streamSecret };
+}
+
+describe('Single-lane sender/receiver roundtrip', () => {
+  test('basic single-chunk transfer', async () => {
+    const { sender, receiver } = await makePair();
+    const plaintext = new TextEncoder().encode('hello shade');
+    const { bytes } = await sender.encryptChunk(plaintext, true);
+    const decrypted = await receiver.decryptChunk(bytes);
+    expect(new TextDecoder().decode(decrypted.plaintext)).toBe('hello shade');
+    expect(decrypted.seq).toBe(0);
+    expect(decrypted.isLast).toBe(true);
+  });
+
+  test('multi-chunk transfer with monotonic seq', async () => {
+    const { sender, receiver } = await makePair();
+    const chunks = ['alpha', 'beta', 'gamma', 'delta'];
+    for (let i = 0; i < chunks.length; i++) {
+      const isLast = i === chunks.length - 1;
+      const { bytes, seq } = await sender.encryptChunk(
+        new TextEncoder().encode(chunks[i]!),
+        isLast,
+      );
+      expect(seq).toBe(i);
+      const dec = await receiver.decryptChunk(bytes);
+      expect(new TextDecoder().decode(dec.plaintext)).toBe(chunks[i]);
+      expect(dec.seq).toBe(i);
+      expect(dec.isLast).toBe(isLast);
+    }
+  });
+
+  test('lane sha256 matches between sender and receiver', async () => {
+    const { sender, receiver } = await makePair();
+    const data = [
+      crypto.randomBytes(1024),
+      crypto.randomBytes(2048),
+      crypto.randomBytes(512),
+    ];
+    for (let i = 0; i < data.length; i++) {
+      const { bytes } = await sender.encryptChunk(data[i]!, i === data.length - 1);
+      await receiver.decryptChunk(bytes);
+    }
+    expect(hex(sender.getLaneSha256Digest())).toBe(hex(receiver.getLaneSha256Digest()));
+  });
+
+  test('handles empty chunks', async () => {
+    const { sender, receiver } = await makePair();
+    const { bytes } = await sender.encryptChunk(new Uint8Array(0), true);
+    const dec = await receiver.decryptChunk(bytes);
+    expect(dec.plaintext.length).toBe(0);
+    expect(dec.isLast).toBe(true);
+  });
+
+  test('ship-gate: ~10 MiB roundtrip preserves byte-for-byte content', async () => {
+    const { sender, receiver } = await makePair();
+    const total = 10 * 1024 * 1024;
+    const chunkSize = 256 * 1024;
+    const allBytes = crypto.randomBytes(total);
+
+    const reconstructed: Uint8Array[] = [];
+    for (let off = 0; off < total; off += chunkSize) {
+      const slice = allBytes.subarray(off, Math.min(off + chunkSize, total));
+      const isLast = off + chunkSize >= total;
+      const { bytes } = await sender.encryptChunk(slice, isLast);
+      const dec = await receiver.decryptChunk(bytes);
+      reconstructed.push(dec.plaintext);
+    }
+
+    let off = 0;
+    for (const piece of reconstructed) {
+      for (let i = 0; i < piece.length; i++) {
+        if (piece[i] !== allBytes[off + i]) {
+          throw new Error(`mismatch at byte ${off + i}`);
+        }
+      }
+      off += piece.length;
+    }
+    expect(off).toBe(total);
+    expect(hex(sender.getLaneSha256Digest())).toBe(hex(receiver.getLaneSha256Digest()));
+  });
+
+  test('byte counters track encrypted/decrypted plaintext', async () => {
+    const { sender, receiver } = await makePair();
+    const a = crypto.randomBytes(100);
+    const b = crypto.randomBytes(250);
+    const { bytes: ab } = await sender.encryptChunk(a, false);
+    const { bytes: bb } = await sender.encryptChunk(b, true);
+    await receiver.decryptChunk(ab);
+    await receiver.decryptChunk(bb);
+    expect(sender.bytesSent).toBe(350n);
+    expect(receiver.bytesReceived).toBe(350n);
+  });
+
+  test('finished flag set after isLast', async () => {
+    const { sender, receiver } = await makePair();
+    const { bytes } = await sender.encryptChunk(new Uint8Array(8), true);
+    expect(sender.isFinished).toBe(true);
+    await receiver.decryptChunk(bytes);
+    expect(receiver.isFinished).toBe(true);
+  });
+
+  test('encryptChunk after finish throws StreamFinishedError', async () => {
+    const { sender } = await makePair();
+    await sender.encryptChunk(new Uint8Array(0), true);
+    await expect(sender.encryptChunk(new Uint8Array(0), false)).rejects.toThrow(
+      StreamFinishedError,
+    );
+  });
+
+  test('decryptChunk after finish throws StreamFinishedError', async () => {
+    const { sender, receiver } = await makePair();
+    const { bytes: a } = await sender.encryptChunk(new Uint8Array(8), true);
+    await receiver.decryptChunk(a);
+    // Try to feed another chunk — sender wouldn't normally produce one, but
+    // simulate an attacker sending bytes after the legitimate isLast.
+    const sender2 = await StreamSender.create({
+      crypto,
+      streamId: (sender as unknown as { streamId: Uint8Array }).streamId,
+      streamSecret: new Uint8Array(32),
+      laneId: 0,
+    });
+    const { bytes: extra } = await sender2.encryptChunk(new Uint8Array(8), false);
+    await expect(receiver.decryptChunk(extra)).rejects.toThrow(StreamFinishedError);
+  });
+
+  test('destroy zeroes the lane key (subsequent calls throw)', async () => {
+    const { sender, receiver } = await makePair();
+    sender.destroy();
+    receiver.destroy();
+    await expect(sender.encryptChunk(new Uint8Array(0), false)).rejects.toThrow(
+      StreamFinishedError,
+    );
+  });
+
+  test('startSeq enables resume from arbitrary offset', async () => {
+    const { sender, receiver } = await makePair({ startSeq: 100 });
+    const { bytes, seq } = await sender.encryptChunk(new TextEncoder().encode('mid'), false);
+    expect(seq).toBe(100);
+    const dec = await receiver.decryptChunk(bytes);
+    expect(dec.seq).toBe(100);
+  });
+});