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-proto/tests/wire.test.ts

@@ -1,5 +1,14 @@
 import { describe, test, expect } from 'bun:test';
-import { encodeEnvelope, decodeEnvelope, encodePreKeyMessage, encodeRatchetMessage } from '../src/index.js';
+import {
+  encodeEnvelope,
+  decodeEnvelope,
+  encodeRatchetMessage,
+  encodeStreamChunk,
+  decodeStreamChunk,
+  inspectEnvelopeType,
+  TYPE_STREAM_CHUNK,
+} from '../src/index.js';
+import type { StreamChunkWire } from '../src/index.js';
 import type { PreKeyMessage, RatchetMessage, ShadeEnvelope } from '@shade/core';
 
 function randBytes(n: number): Uint8Array {
@@ -173,13 +182,124 @@ describe('Wire Format', () => {
     });
 
     test('rejects unknown type', () => {
-      const data = new Uint8Array([0x01, 0xFF]);
+      const data = new Uint8Array([0x02, 0xFF]);
       expect(() => decodeEnvelope(data)).toThrow('Unknown type');
     });
 
     test('rejects too-short data', () => {
-      expect(() => decodeEnvelope(new Uint8Array([0x01]))).toThrow('Too short');
+      expect(() => decodeEnvelope(new Uint8Array([0x02]))).toThrow('Too short');
       expect(() => decodeEnvelope(new Uint8Array([]))).toThrow('Too short');
     });
   });
+
+  // ─── StreamChunk (type 0x11) ───────────────────────────────
+
+  describe('StreamChunk', () => {
+    function makeChunk(overrides: Partial<StreamChunkWire> = {}): StreamChunkWire {
+      return {
+        streamId: randBytes(16),
+        laneId: 0,
+        seq: 0n,
+        isLast: false,
+        nonce: randBytes(12),
+        aad: new Uint8Array(0),
+        ciphertext: randBytes(64),
+        ...overrides,
+      };
+    }
+
+    test('encode/decode roundtrip', () => {
+      const c = makeChunk({ laneId: 7, seq: 42n, isLast: true });
+      const encoded = encodeStreamChunk(c);
+      const decoded = decodeStreamChunk(encoded);
+      expect(decoded.streamId).toEqual(c.streamId);
+      expect(decoded.laneId).toBe(7);
+      expect(decoded.seq).toBe(42n);
+      expect(decoded.isLast).toBe(true);
+      expect(decoded.nonce).toEqual(c.nonce);
+      expect(decoded.aad.length).toBe(0);
+      expect(decoded.ciphertext).toEqual(c.ciphertext);
+    });
+
+    test('emits the correct type tag', () => {
+      const encoded = encodeStreamChunk(makeChunk());
+      expect(encoded[0]).toBe(0x02); // version
+      expect(encoded[1]).toBe(TYPE_STREAM_CHUNK);
+    });
+
+    test('handles empty ciphertext', () => {
+      const c = makeChunk({ ciphertext: new Uint8Array(0) });
+      const decoded = decodeStreamChunk(encodeStreamChunk(c));
+      expect(decoded.ciphertext.length).toBe(0);
+    });
+
+    test('handles 16 MiB ciphertext (max chunk + tag)', () => {
+      const c = makeChunk({ ciphertext: randBytes(16 * 1024 * 1024 + 16) });
+      const encoded = encodeStreamChunk(c);
+      const decoded = decodeStreamChunk(encoded);
+      expect(decoded.ciphertext.length).toBe(c.ciphertext.length);
+    });
+
+    test('handles MAX_SEQ', () => {
+      const max = 0xffff_ffff_ffff_ffffn;
+      const c = makeChunk({ seq: max });
+      const decoded = decodeStreamChunk(encodeStreamChunk(c));
+      expect(decoded.seq).toBe(max);
+    });
+
+    test('rejects wrong-length streamId', () => {
+      expect(() => encodeStreamChunk(makeChunk({ streamId: randBytes(15) }))).toThrow();
+    });
+
+    test('rejects wrong-length nonce', () => {
+      expect(() => encodeStreamChunk(makeChunk({ nonce: randBytes(11) }))).toThrow();
+    });
+
+    test('rejects out-of-range laneId', () => {
+      expect(() => encodeStreamChunk(makeChunk({ laneId: 0x1_0000_0000 }))).toThrow();
+      expect(() => encodeStreamChunk(makeChunk({ laneId: -1 }))).toThrow();
+    });
+
+    test('decode rejects wrong type tag', () => {
+      const valid = encodeStreamChunk(makeChunk());
+      const tampered = valid.slice();
+      tampered[1] = 0x02; // ratchet
+      expect(() => decodeStreamChunk(tampered)).toThrow();
+    });
+
+    test('decode rejects wrong version', () => {
+      const valid = encodeStreamChunk(makeChunk());
+      const tampered = valid.slice();
+      tampered[0] = 0x01; // bumped to 0x02 in v0.3.0; 0x01 is the legacy version
+      expect(() => decodeStreamChunk(tampered)).toThrow();
+    });
+
+    test('decode rejects truncated body', () => {
+      const valid = encodeStreamChunk(makeChunk());
+      expect(() => decodeStreamChunk(valid.slice(0, valid.length - 5))).toThrow();
+    });
+
+    test('decode rejects body extended beyond ctLen', () => {
+      const valid = encodeStreamChunk(makeChunk());
+      const tampered = new Uint8Array(valid.length + 1);
+      tampered.set(valid);
+      expect(() => decodeStreamChunk(tampered)).toThrow();
+    });
+
+    test('inspectEnvelopeType identifies stream-chunk', () => {
+      expect(inspectEnvelopeType(encodeStreamChunk(makeChunk()))).toBe('stream-chunk');
+    });
+
+    test('inspectEnvelopeType identifies ratchet/prekey/unknown', () => {
+      const ratchet: ShadeEnvelope = {
+        type: 'ratchet',
+        content: makeRatchetMessage(),
+        timestamp: 0,
+        senderAddress: '',
+      };
+      expect(inspectEnvelopeType(encodeEnvelope(ratchet))).toBe('ratchet');
+      expect(inspectEnvelopeType(new Uint8Array([0x02, 0x99]))).toBe('unknown');
+      expect(inspectEnvelopeType(new Uint8Array([]))).toBe('unknown');
+    });
+  });
 });