feat(homecore-migrate/p1): ADR-134 .storage parser + entity-registry import (19 tests pass)

- HaStorageEnvelope: outer {version, minor_version, key, data} shape for all .storage files
- storage_format/v13: versioned parser dispatch; UnsupportedSchemaVersion hard error on unknown minor_version
- entity_registry: core.entity_registry v13 → Vec<homecore::EntityEntry> with full field mapping
- device_registry: core.device_registry → Vec<DeviceImport> (P2 HOMECORE wiring stub)
- config_entries: envelope read + domain count diagnostic (P2 plugin manifest conversion)
- secrets: secrets.yaml → HashMap<String,String>
- automations: count + ID list extraction (P2 conversion)
- cli: clap-derived Inspect/ImportEntities/ImportDevices/InspectConfigEntries/InspectSecrets/InspectAutomations subcommands
- 19 unit tests, all pass; build clean; workspace member appended to v2/Cargo.toml

Co-Authored-By: claude-flow <ruv@ruv.net>

v2/Cargo.lock

@@ -3457,6 +3457,20 @@ dependencies = [
  "uuid",
 ]
 
+[[package]]
+name = "homecore-assist"
+version = "0.1.0-alpha.0"
+dependencies = [
+ "async-trait",
+ "homecore",
+ "regex",
+ "serde",
+ "serde_json",
+ "thiserror 1.0.69",
+ "tokio",
+ "tracing",
+]
+
 [[package]]
 name = "homecore-automation"
 version = "0.1.0-alpha.0"