feat: initial implementation of content-addressed incremental backup engine

Rust-centric architecture with TypeScript facade following smartproxy/smartstorage pattern.
Core engine in Rust (FastCDC chunking, SHA-256, gzip, AES-256-GCM + Argon2id, binary pack files,
global index, snapshots, locking, verification, pruning, repair). TypeScript provides npm interface
via @push.rocks/smartrust RustBridge IPC with Unix socket streaming for ingest/restore.
All 14 integration tests pass.

ts/interfaces.ts

@@ -0,0 +1,219 @@
+import type { ICommandDefinition } from '@push.rocks/smartrust';
+
+// ==================== Repository Config ====================
+
+export interface IRepositoryConfig {
+  version: number;
+  id: string;
+  createdAt: string;
+  chunking: IChunkingConfig;
+  compression: string;
+  encryption?: IEncryptionConfig;
+  packTargetSize: number;
+}
+
+export interface IChunkingConfig {
+  algorithm: string;
+  minSize: number;
+  avgSize: number;
+  maxSize: number;
+}
+
+export interface IEncryptionConfig {
+  algorithm: string;
+  kdf: string;
+  kdfParams: IKdfParams;
+}
+
+export interface IKdfParams {
+  memory: number;
+  iterations: number;
+  parallelism: number;
+}
+
+// ==================== Snapshots ====================
+
+export interface ISnapshot {
+  id: string;
+  version: number;
+  createdAt: string;
+  tags: Record<string, string>;
+  originalSize: number;
+  storedSize: number;
+  chunkCount: number;
+  newChunks: number;
+  reusedChunks: number;
+  items: ISnapshotItem[];
+}
+
+export interface ISnapshotItem {
+  name: string;
+  type: string;
+  size: number;
+  chunks: string[];
+}
+
+export interface ISnapshotFilter {
+  tags?: Record<string, string>;
+  after?: string;
+  before?: string;
+}
+
+// ==================== Ingest ====================
+
+export interface IInitOptions {
+  passphrase?: string;
+  chunking?: Partial<IChunkingConfig>;
+  packTargetSize?: number;
+}
+
+export interface IOpenOptions {
+  passphrase?: string;
+}
+
+export interface IIngestOptions {
+  tags?: Record<string, string>;
+  items?: IIngestItemOptions[];
+}
+
+export interface IIngestItemOptions {
+  name: string;
+  type?: string;
+}
+
+export interface IIngestItem {
+  stream: NodeJS.ReadableStream;
+  name: string;
+  type?: string;
+}
+
+// ==================== Restore ====================
+
+export interface IRestoreOptions {
+  item?: string;
+}
+
+// ==================== Maintenance ====================
+
+export interface IVerifyOptions {
+  level?: 'quick' | 'standard' | 'full';
+}
+
+export interface IVerifyResult {
+  ok: boolean;
+  errors: IVerifyError[];
+  stats: {
+    packsChecked: number;
+    chunksChecked: number;
+    snapshotsChecked: number;
+  };
+}
+
+export interface IVerifyError {
+  pack?: string;
+  chunk?: string;
+  snapshot?: string;
+  error: string;
+}
+
+export interface IRetentionPolicy {
+  keepLast?: number;
+  keepDays?: number;
+  keepWeeks?: number;
+  keepMonths?: number;
+}
+
+export interface IPruneResult {
+  removedSnapshots: number;
+  removedPacks: number;
+  freedBytes: number;
+  dryRun: boolean;
+}
+
+export interface IRepairResult {
+  indexRebuilt: boolean;
+  indexedChunks: number;
+  staleLocksRemoved: number;
+  errors: string[];
+}
+
+export interface IUnlockOptions {
+  force?: boolean;
+}
+
+// ==================== Events ====================
+
+export interface IIngestProgress {
+  operation: string;
+  percentage: number;
+  message: string;
+}
+
+export interface IIngestComplete {
+  snapshotId: string;
+  originalSize: number;
+  storedSize: number;
+  newChunks: number;
+  reusedChunks: number;
+}
+
+// ==================== IPC Command Map ====================
+
+export type TContainerArchiveCommands = {
+  init: ICommandDefinition<
+    { path: string; passphrase?: string },
+    IRepositoryConfig
+  >;
+  open: ICommandDefinition<
+    { path: string; passphrase?: string },
+    IRepositoryConfig
+  >;
+  close: ICommandDefinition<
+    Record<string, never>,
+    Record<string, never>
+  >;
+  ingest: ICommandDefinition<
+    {
+      socketPath: string;
+      tags?: Record<string, string>;
+      items?: IIngestItemOptions[];
+    },
+    { snapshot: ISnapshot }
+  >;
+  restore: ICommandDefinition<
+    {
+      snapshotId: string;
+      socketPath: string;
+      item?: string;
+    },
+    Record<string, never>
+  >;
+  listSnapshots: ICommandDefinition<
+    { filter?: ISnapshotFilter },
+    { snapshots: ISnapshot[] }
+  >;
+  getSnapshot: ICommandDefinition<
+    { snapshotId: string },
+    { snapshot: ISnapshot }
+  >;
+  verify: ICommandDefinition<
+    { level: string },
+    IVerifyResult
+  >;
+  repair: ICommandDefinition<
+    Record<string, never>,
+    IRepairResult
+  >;
+  prune: ICommandDefinition<
+    { retention: IRetentionPolicy; dryRun?: boolean },
+    IPruneResult
+  >;
+  reindex: ICommandDefinition<
+    Record<string, never>,
+    { indexedChunks: number }
+  >;
+  unlock: ICommandDefinition<
+    { force?: boolean },
+    { removedLocks: number }
+  >;
+};