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/envelope.test.ts

@@ -0,0 +1,92 @@
+import { describe, test, expect } from 'bun:test';
+import { ValidationError } from '@shade/core';
+import {
+  encodeStreamControl,
+  parseStreamControl,
+  isStreamControlMessage,
+} from '../src/index.js';
+import type {
+  StreamInitMessage,
+  StreamFinishMessage,
+  StreamAbortMessage,
+} from '../src/index.js';
+
+describe('control envelope encode/parse roundtrip', () => {
+  test('stream-init', () => {
+    const msg: StreamInitMessage = {
+      kind: 'shade.stream-init/v1',
+      streamId: 'AAAAAAAAAAAAAAAAAAAAAA',
+      streamSecret: 'BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBA',
+      metadata: {
+        name: 'world.zip',
+        sizeBytes: 1024,
+        contentType: 'application/zip',
+        chunkSize: 256,
+        totalChunks: 4,
+        sentAt: 1730000000000,
+      },
+      lanes: [
+        {
+          laneId: 0,
+          partition: { kind: 'range', startByte: 0, endByte: 512, startChunk: 0 },
+        },
+        {
+          laneId: 1,
+          partition: { kind: 'range', startByte: 512, endByte: 1024, startChunk: 0 },
+        },
+      ],
+    };
+    const json = encodeStreamControl(msg);
+    expect(parseStreamControl(json)).toEqual(msg);
+  });
+
+  test('stream-finish', () => {
+    const msg: StreamFinishMessage = {
+      kind: 'shade.stream-finish/v1',
+      streamId: 'AAAAAAAAAAAAAAAAAAAAAA',
+      laneSha256: [{ laneId: 0, sha256: 'abcd', chunkCount: 1, byteCount: 256 }],
+      overallSha256: 'efgh',
+      finishedAt: 1730000001000,
+    };
+    expect(parseStreamControl(encodeStreamControl(msg))).toEqual(msg);
+  });
+
+  test('stream-abort', () => {
+    const msg: StreamAbortMessage = {
+      kind: 'shade.stream-abort/v1',
+      streamId: 'AAAAAAAAAAAAAAAAAAAAAA',
+      reason: 'sender-cancel',
+      message: 'user clicked cancel',
+      abortedAt: 1730000002000,
+    };
+    expect(parseStreamControl(encodeStreamControl(msg))).toEqual(msg);
+  });
+
+  test('rejects malformed JSON', () => {
+    expect(() => parseStreamControl('not-json')).toThrow(ValidationError);
+  });
+
+  test('rejects messages without a kind field', () => {
+    expect(() => parseStreamControl(JSON.stringify({ foo: 'bar' }))).toThrow(ValidationError);
+  });
+
+  test('rejects messages whose kind does not start with shade.stream-', () => {
+    expect(() => parseStreamControl(JSON.stringify({ kind: 'other.kind' }))).toThrow(
+      ValidationError,
+    );
+  });
+});
+
+describe('isStreamControlMessage', () => {
+  test('returns true for valid shapes', () => {
+    expect(isStreamControlMessage({ kind: 'shade.stream-init/v1' })).toBe(true);
+    expect(isStreamControlMessage({ kind: 'shade.stream-finish/v1' })).toBe(true);
+  });
+
+  test('returns false for non-objects and missing kind', () => {
+    expect(isStreamControlMessage(null)).toBe(false);
+    expect(isStreamControlMessage(42)).toBe(false);
+    expect(isStreamControlMessage({})).toBe(false);
+    expect(isStreamControlMessage({ kind: 'unrelated' })).toBe(false);
+  });
+});