refactor(enclave): restructure enclave to use go-pdk and support WASM target

AGENTS.md

@@ -170,16 +170,22 @@ if err != nil {
 
 ```
 motr-enclave/
-├── main.go           # Plugin entry point, exported functions
-├── db/
-│   ├── schema.sql    # Database schema
-│   ├── query.sql     # SQLC query definitions
-│   └── *.go          # Generated SQLC code
-├── sqlc.yaml         # SQLC configuration
-├── Makefile          # Build commands
-└── go.mod            # Go module
+├── cmd/
+│   └── enclave/
+│       └── main.go       # Plugin entry point (WASM-only, go-pdk imports)
+├── internal/
+│   ├── keybase/          # Database access layer
+│   ├── crypto/           # Cryptographic operations
+│   ├── state/            # Plugin state management (WASM-only)
+│   ├── types/            # Input/output type definitions
+│   └── migrations/       # Database migrations
+├── sqlc.yaml             # SQLC configuration
+├── Makefile              # Build commands
+└── go.mod                # Go module
 ```
 
+Note: Files with `//go:build wasip1` constraint (cmd/enclave/, internal/state/) only compile for WASM target.
+
 ## Dependencies
 
 Install with `make deps`: