feat: introduce global meta store and root store concept, and update CLI to manage active store

docs/architecture.md

@@ -187,14 +187,14 @@ Note: KV stores multiple heads per key to support DAG conflict resolution. Reads
 ```
 Table              Key                     Value                      Purpose
 ─────────────────────────────────────────────────────────────────────────────
-stores             UUID (store_id)         StoreInfo                  Known stores this node participates in
-meta               String                  Vec<u8>                    Global metadata (node_id, etc.)
+stores             [u8; 16] (UUID)         u64 (created_at_ms)        Known stores
+meta               "root_store"            [u8; 16] (UUID)            Root store ID (opened on startup)
 ```
 
-StoreInfo: `{ type: "manifest" | "data", name, created_at, ... }`
-- Manifest stores define mesh membership via KV entries (`/nodes/{pubkey}/...`)
+- **Root Store**: The primary/manifest store for this node, auto-opened on CLI startup
+- **Stores Table**: Tracks all stores this node participates in
+- Manifest stores define mesh membership via `/nodes/{pubkey}/...` entries
 - Data stores hold application data
-- Node's list of manifest store IDs = meshes it belongs to
 
 #### In-Memory Structures
 

docs/roadmap.md

@@ -21,16 +21,15 @@
 - Can replay log to reconstruct KV state
 - All operations survive restart
 
-### Multi-KV Refactoring (before M2)
+### Multi-KV Refactoring (before M2) ✓
 
-Current code assumes single store. Changes needed:
-- [ ] DataDir → support `stores/{uuid}/` subdirectories
-- [ ] SigChain → scoped to (store_id, author_id)
-- [ ] Store → per-store state.db, not global
-- [ ] Log paths → `stores/{uuid}/logs/{author}.log`
-- [ ] Add global meta.db for stores table
-- [ ] Proto: SignedEntry/messages need store_id (UUID)
-- [ ] CLI → `create-store`, `list-stores`, `use <store>`
+- [x] DataDir → `stores/{uuid}/` subdirectories
+- [x] Store → per-store state.db
+- [x] Log paths → `stores/{uuid}/logs/{author}.log`
+- [x] Proto: Entry has store_id (UUID)
+- [x] CLI → `init`, `create-store`, `list-stores`, `use`
+- [x] meta.db stores table (MetaStore)
+- [x] SigChain → validate entry.store_id
 
 ---
 

docs/storage.md

@@ -0,0 +1,39 @@
+# Storage Format
+
+## Directory Layout
+
+```
+~/.local/share/lattice/
+├── identity.key              # Ed25519 private key (not replicated)
+├── meta.db                   # Global metadata (redb)
+└── stores/{uuid}/
+    ├── logs/{author}.log     # Append-only SignedEntry stream
+    └── state.db              # Per-store KV state (redb)
+```
+
+## meta.db (redb)
+
+| Table   | Key           | Value              | Purpose                      |
+|---------|---------------|--------------------|------------------------------|
+| stores  | UUID (16B)    | created_at (u64)   | Known stores                 |
+| meta    | "root_store"  | UUID (16B)         | Auto-opened on CLI startup   |
+
+## state.db (redb, per store)
+
+| Table   | Key      | Value       | Purpose                |
+|---------|----------|-------------|------------------------|
+| kv      | String   | Vec<u8>     | Key-value data         |
+| meta    | String   | Vec<u8>     | last_seq, last_hash    |
+
+## Log Files
+
+Each `{author}.log` contains length-delimited `LogRecord` messages:
+
+```protobuf
+message LogRecord {
+  bytes hash = 1;         // BLAKE3 hash of entry_bytes
+  bytes entry_bytes = 2;  // Serialized SignedEntry
+}
+```
+
+Hashes are verified on read; corruption causes `LogError::HashMismatch`.