HyperVault integration: cloud mind ⇄ sovereign chain + archive

CHANGELOG.md

@@ -4,6 +4,42 @@ All notable changes to AgentVault will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
+## [Unreleased] - HyperVault integration
+
+### Added
+- **HyperVault ⇄ AgentVault bridge (`src/hypervault/`, `agentvault hypervault`).**
+  Makes the HyperVault cloud mind a first-class citizen across three tiers —
+  hot (cloud), warm (ICP canister), cold (Arweave):
+  - `HyperVaultClient` — typed REST client over undici with retry/backoff and
+    streamed NDJSON export (`GET /api/export`), plus import and archive-receipt
+    endpoints.
+  - `agentvault-hypervault-snapshot-v1` bundle format — reuses the
+    thoughtform-bundle envelope with per-entry SHA-256, a Merkle root, and an
+    ed25519 manifest signature. Encryption via the audited `CanisterEncryption`
+    (AES-256-GCM); private artifacts and conversations are always encrypted.
+  - Local indices — pure-TS weighted FTS index and a cosine `VectorIndex` over
+    exported embeddings, with reciprocal-rank hybrid recall and graceful
+    FTS-only fallback.
+  - Backbone/wiki adapters — `HyperVaultMemoryStore`, `HyperVaultKnowledgeStore`,
+    `HyperVaultWikiStore` run the existing interfaces against the cloud mind.
+  - On-chain mind mirror — topological, idempotent DAG replay onto a
+    `memory_repo` canister, with on-chain archive receipts.
+  - CLI: `hypervault connect · status · bootstrap · pull · push · snapshot ·
+    archive · verify · restore · reindex · recall`; `init --hypervault`.
+  - Native MCP server — `agentvault mcp serve` (stdio JSON-RPC, no new
+    dependency) exposing the `hypervault_*` pipeline tools and the existing
+    `wiki_*` tools.
+  - New package export subpath `agentvault/hypervault`.
+
+### Security
+- **C-1 (CRITICAL):** `vetkeys.decryptJSON` now validates the AES-256-GCM /
+  ChaCha20-Poly1305 authentication tag before returning plaintext (previously
+  `setAuthTag` was never called, so tampered ciphertext decrypted silently).
+  `EncryptedData` gains an optional `tag` field, a matching `encryptJSON` helper
+  is added, and payloads with no usable tag are refused rather than decrypted
+  unauthenticated. Legacy combined-layout payloads (tag appended to ciphertext)
+  are still supported.
+
 ## [1.0.4] - 2026-05-24 - Security & build hygiene refresh
 
 ### Security

README.md

@@ -93,6 +93,27 @@ agentvault show --canister-id <your-canister-id>
 agentvault fetch --canister-id <your-canister-id>
 ```
 
+## HyperVault
+
+[HyperVault](https://github.com/johnnyclem/hypervault) is the living cloud mind
+(`hypervault.store`); AgentVault is the sovereign body. The `hypervault` command
+group bridges them across three tiers — hot (cloud), warm (ICP canister), cold
+(Arweave) — so a cloud account becomes reconstructible from chain alone.
+
+```bash
+# Bootstrap a HyperVault-backed agent — memories, mind history, and indices included
+npx agentvault@latest hypervault bootstrap my-agent --key hv_...
+
+# hypervault.store → fully secure, archived, blockchain-backed AgentVault
+npx agentvault@latest hypervault archive --all --encrypt --network ic --arweave
+
+# Resurrect anywhere from a single Arweave transaction
+npx agentvault@latest hypervault restore ar://<tx-id> --to local
+```
+
+Both one-liners are also MCP tools via the native `agentvault mcp serve` server.
+See [`docs/guides/hypervault.md`](docs/guides/hypervault.md) for the full guide.
+
 ## CLI Commands
 
 ### Core Commands