v3.56.3 — AgentDB alpha.20, memory 3.0.3, sql.js lock guard

Patch release: AgentDB 3.0.0-alpha.20 update. @claude-flow/memory 3.0.3 (published standalone; the CLI pins it exactly) and @claude-flow/cli / claude-flow / ruflo 3.56.3. neural, shared, cli-core unchanged.

Changed

• AgentDB floor ^3.0.0-alpha.17 -> ^3.0.0-alpha.20 (memory, cli, root, ruflo). alpha.20 swaps @xenova/transformers for @huggingface/transformers, @ruvector/rvf 0.1.9 -> 0.2.3, ruvector -> 0.2.x.
• Search scores shift slightly (same-text cosine ~0.992 vs alpha.17): an entry that scored just under the 0.3 default threshold can now appear just above it, ranked far below the exact-keyword hit. One regression-test assertion was adjusted for this (PR #3960).

Fixed

• sql.js stale <db>.agentdb.lock: AgentDB alpha.20 refuses saves while the lock exists, and a lock left by a crashed writer was never cleared, so every later save failed and the db file was never created. @claude-flow/memory now clears the lock only when provably stale (regular file named exactly <db>.agentdb.lock, numeric dead PID, >10 s old, atomic rename-aside + re-verify), retries once, otherwise throws AgentdbLockError. A failed persist on shutdown is now surfaced (ControllerRegistry, AgentDBBackend, HybridBackend, shutdownBridge) instead of swallowed. Affects only the sql.js path (no native better-sqlite3).
• Dev tree only: pnpm.packageExtensions declares onnxruntime-common for @huggingface/transformers@4.2.0.

Known / not verified

• agentdb 3.0.0-alpha.20 has no npm provenance attestation (registry signature present).
• Under pnpm 4.2.0 the embedder fell back to mock embeddings before the extension above; npm installs resolve transformers 4.3.1 and were unaffected.
• AgentDB forceWasm: true still selects better-sqlite3 unless AGENTDB_FORCE_SQLJS=1 (upstream behaviour).

PR #3960.