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-files/tests/integration/read-write-inline.test.ts

@@ -0,0 +1,138 @@
+import { describe, test, expect, beforeAll, afterAll } from 'bun:test';
+import { sha256 } from '@noble/hashes/sha2.js';
+import { NotFoundError, type FileEntry } from '../../src/index.js';
+import type { UserReadResult, UserWriteArgs, WriteResult } from '../../src/server/io-types.js';
+import type { OpContext } from '../../src/server/handler-context.js';
+import { setupFileRig, type FileTestRig } from './helpers/rig.js';
+
+interface StoredBlob {
+  bytes: Uint8Array;
+  contentType?: string;
+  sha256: string;
+  mtime: number;
+}
+
+function bytesToHex(b: Uint8Array): string {
+  return Array.from(b, (x) => x.toString(16).padStart(2, '0')).join('');
+}
+
+describe('Content I/O — inline read/write E2E', () => {
+  let rig: FileTestRig;
+  const blobs = new Map<string, StoredBlob>();
+
+  beforeAll(async () => {
+    blobs.clear();
+    rig = await setupFileRig({
+      read: async (ctx: OpContext<{ path: string }>): Promise<UserReadResult> => {
+        const blob = blobs.get(ctx.path);
+        if (blob === undefined) throw new NotFoundError(ctx.path);
+        return blob.contentType !== undefined
+          ? { kind: 'inline', bytes: blob.bytes, sha256: blob.sha256, contentType: blob.contentType }
+          : { kind: 'inline', bytes: blob.bytes, sha256: blob.sha256 };
+      },
+      write: async (ctx: OpContext<UserWriteArgs>): Promise<WriteResult> => {
+        const args = ctx.args;
+        if (args.content.kind !== 'inline') {
+          throw new Error('expected inline content for this test');
+        }
+        if (blobs.has(args.path) && !args.overwrite) {
+          throw new Error('exists');
+        }
+        const stored: StoredBlob = {
+          bytes: args.content.bytes,
+          ...(args.contentType !== undefined ? { contentType: args.contentType } : {}),
+          sha256: args.content.sha256,
+          mtime: Date.now(),
+        };
+        blobs.set(args.path, stored);
+        const entry: FileEntry = {
+          name: args.path.split('/').filter(Boolean).pop() ?? '',
+          kind: 'file',
+          size: args.content.size,
+          mtime: stored.mtime,
+          ...(args.contentType !== undefined ? { contentType: args.contentType } : {}),
+          metadata: { sha256: args.content.sha256 },
+        };
+        return { entry };
+      },
+    });
+  });
+
+  afterAll(async () => {
+    await rig.teardown();
+  });
+
+  test('write 1 KiB inline → read it back, sha256 matches', async () => {
+    const data = new Uint8Array(1024);
+    for (let i = 0; i < data.length; i++) data[i] = (i * 7) & 0xff;
+    const expectedSha = bytesToHex(sha256(data));
+
+    const writeResult = await rig.fs.write('/small.bin', data, { contentType: 'application/octet-stream' });
+    expect(writeResult.entry.size).toBe(1024);
+    expect(writeResult.entry.metadata.sha256).toBe(expectedSha);
+
+    const readResult = await rig.fs.read('/small.bin');
+    expect(readResult.kind).toBe('inline');
+    if (readResult.kind === 'inline') {
+      expect(readResult.bytes.byteLength).toBe(1024);
+      expect(readResult.sha256).toBe(expectedSha);
+      expect(readResult.contentType).toBe('application/octet-stream');
+      expect(Array.from(readResult.bytes)).toEqual(Array.from(data));
+    }
+  });
+
+  test('write 100 KiB inline → read it back, sha256 matches', async () => {
+    const data = new Uint8Array(100 * 1024);
+    crypto.getRandomValues(data);
+    const expectedSha = bytesToHex(sha256(data));
+
+    await rig.fs.write('/big.bin', data);
+    const readResult = await rig.fs.read('/big.bin');
+    expect(readResult.kind).toBe('inline');
+    if (readResult.kind === 'inline') {
+      expect(readResult.bytes.byteLength).toBe(100 * 1024);
+      expect(readResult.sha256).toBe(expectedSha);
+      expect(Array.from(readResult.bytes)).toEqual(Array.from(data));
+    }
+  });
+
+  test('overwrite without flag → server-defined error; with flag → succeeds', async () => {
+    const a = new Uint8Array([1, 2, 3]);
+    const b = new Uint8Array([4, 5, 6]);
+    await rig.fs.write('/dup.bin', a);
+    await expect(rig.fs.write('/dup.bin', b)).rejects.toThrow();
+    await rig.fs.write('/dup.bin', b, { overwrite: true });
+    const out = await rig.fs.read('/dup.bin');
+    expect(out.kind).toBe('inline');
+    if (out.kind === 'inline') {
+      expect(Array.from(out.bytes)).toEqual([4, 5, 6]);
+    }
+  });
+
+  test('write Blob input → inferred contentType, round-trips', async () => {
+    const blob = new Blob([new Uint8Array([0xde, 0xad, 0xbe, 0xef])], { type: 'image/png' });
+    await rig.fs.write('/blobby.png', blob);
+    const out = await rig.fs.read('/blobby.png');
+    expect(out.kind).toBe('inline');
+    if (out.kind === 'inline') {
+      expect(out.contentType).toBe('image/png');
+      expect(Array.from(out.bytes)).toEqual([0xde, 0xad, 0xbe, 0xef]);
+    }
+  });
+
+  test('read non-existent → NotFoundError', async () => {
+    await expect(rig.fs.read('/missing.bin')).rejects.toThrow();
+  });
+
+  test('inline path also handles 256 KiB exactly (boundary)', async () => {
+    const data = new Uint8Array(256 * 1024);
+    crypto.getRandomValues(data);
+    const expectedSha = bytesToHex(sha256(data));
+    await rig.fs.write('/boundary.bin', data);
+    const out = await rig.fs.read('/boundary.bin');
+    expect(out.kind).toBe('inline');
+    if (out.kind === 'inline') {
+      expect(out.sha256).toBe(expectedSha);
+    }
+  });
+});