[txfei]

Scope

• Hy Memory SDK Client: remove migration-only and duplicate raw read methods.
• MemHub App migration: make stopped-writer startup migration the isolated privileged data-plane access exception.
• MemHub HTTP raw history: keep the existing endpoint, backed by unified list_memories().

Changes

• Remove public import_raw / async_import_raw.
• Remove public import_memory_exact / async_import_memory_exact.
• Remove public get_raw / async_get_raw and list_raw / async_list_raw.
• Remove include_raw from get(); exact lookup returns the actual matched layer (raw_id -> l1_raw, fact ID -> fact layer).
• Make explicit raw listing use list_memories(layers=[\"l1_raw\"]); add generic session/source list filters and include the original source in list/get results. Backend provenance is now retrieval_source instead of overwriting source with vdb/graph.
• Move exact legacy writes and raw inventory access into hy_sdk_migration.py, which directly accesses SDK stores only while Runtime writers are stopped. Semantic migration writes both vector and graph projections.
• Backfill a complete same-filesystem staging copy, preserving SDK-only records. Cutover atomically swaps SDK roots, rolls back on pre-commit failure, and recovers interrupted swaps on restart.
• Refuse to start Runtime while startup migration is deferred or blocked.
• Keep get_write_outcome() public because it is required by the normal durable write queue, not migration.
• Keep private SDK access forbidden everywhere except existing Graph projection and this exact offline migration module.

Historical MemHub versions already wrote to the SDK and stored hy_memory_id mappings, so migration still validates existing records internally. This prevents duplicate raw/memory rows without creating public Client APIs.

Verification

• Focused SDK contracts: 42 passed.
• Core staging/migration/CLI/architecture target: 50 passed.
• Earlier full affected Core target: 230 passed.
• Desktop suite: 473 passed; TypeScript typecheck passed.
• SDK and Core Ruff checks passed.
• Core test index remains current (322 files).