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/hash.test.ts

@@ -0,0 +1,72 @@
+import { describe, test, expect } from 'bun:test';
+import { StreamingSha256, sha256Once } from '../src/index.js';
+
+function hex(bytes: Uint8Array): string {
+  return Array.from(bytes, (b) => b.toString(16).padStart(2, '0')).join('');
+}
+
+async function subtleHashHex(data: Uint8Array): Promise<string> {
+  const buf = await globalThis.crypto.subtle.digest('SHA-256', data as unknown as ArrayBuffer);
+  return hex(new Uint8Array(buf));
+}
+
+describe('StreamingSha256', () => {
+  test('digest of empty input matches the well-known SHA-256 zero hash', () => {
+    const h = new StreamingSha256().digest();
+    expect(hex(h)).toBe('e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855');
+  });
+
+  test('matches one-shot sha256 over the same bytes', () => {
+    const data = new TextEncoder().encode('the quick brown fox');
+    const streaming = new StreamingSha256().update(data).digest();
+    expect(hex(streaming)).toBe(hex(sha256Once(data)));
+  });
+
+  test('matches SubtleCrypto digest over the same bytes', async () => {
+    const data = new TextEncoder().encode('cross-impl parity check');
+    const streaming = new StreamingSha256().update(data).digest();
+    expect(hex(streaming)).toBe(await subtleHashHex(data));
+  });
+
+  test('chunked updates produce identical digest to a single update', () => {
+    const buf = new Uint8Array(4096);
+    for (let i = 0; i < buf.length; i++) buf[i] = i & 0xff;
+    const a = new StreamingSha256().update(buf).digest();
+    const b = new StreamingSha256();
+    for (let off = 0; off < buf.length; off += 137) {
+      b.update(buf.slice(off, Math.min(off + 137, buf.length)));
+    }
+    expect(hex(a)).toBe(hex(b.digest()));
+  });
+
+  test('handles multi-megabyte inputs (memory-bounded streaming)', () => {
+    const chunk = new Uint8Array(1024 * 1024);
+    for (let i = 0; i < chunk.length; i++) chunk[i] = (i * 31) & 0xff;
+    const h = new StreamingSha256();
+    for (let i = 0; i < 4; i++) h.update(chunk);
+    const digest = h.digest();
+    expect(digest.length).toBe(32);
+  });
+
+  test('throws on update after digest()', () => {
+    const h = new StreamingSha256();
+    h.digest();
+    expect(() => h.update(new Uint8Array([1]))).toThrow();
+  });
+
+  test('isFinalized reflects digest()', () => {
+    const h = new StreamingSha256();
+    expect(h.isFinalized).toBe(false);
+    h.digest();
+    expect(h.isFinalized).toBe(true);
+  });
+
+  test('skips no-op empty updates', () => {
+    const h = new StreamingSha256();
+    h.update(new Uint8Array(0));
+    h.update(new Uint8Array(0));
+    expect(hex(h.digest())).toBe(
+      'e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855',
+    );
+  });
+});