v0.1.9 — Reduce idle resource use and reuse index shards

Idle MCP sessions could repeatedly scan large repositories, retain index workers, and keep cancelled retrieval work running. Version 0.1.9 bounds background resource use and makes saved-file updates reuse existing source and vector data.

• Pause background scans after 60 seconds without search activity; unload idle generations and release workspace leases after 120 seconds. Workers exit after their lease grace period when no requests or admitted builds remain.
• Reuse unchanged source text, parsed units, lexical features, and immutable vector shards. Existing embedding caches migrate without new model requests for cached vectors.
• Propagate cancellation and deadlines through retrieval queues, model requests, and parser subprocesses.
• Limit resident workspaces, concurrent builds, source/index size, and retained vector storage. Back off on repeated failures and reclaim abandoned generations.
• Use metadata-validated source hashes on macOS/Linux with periodic full reconciliation. Set OCE_STRICT_FRESHNESS=1 to reread content for every freshness check; Windows keeps strict checks by default.

Validation: local Node and Python suites, Linux/macOS/Windows platform CI, isolated archive installation and setup/doctor, and real-model MCP search before and after a saved-file edit. A 48,870-file CAD cache migrated 163,886 units without new embedding requests and restored successfully after unloading.

Upgrade with npm install -g open-context-engine@0.1.9, then restart connected MCP clients. Resource controls are documented in Quickstart. The release includes the verified npm archive and its SHA-256 checksum.