Summary

PR B of #12139 — the external-only Chroma lifecycle cleanup, completing the ticket. With the orchestrator daemon as the sole Chroma driver (#12065) and the manage_database MCP tool retired (PR A / #12197), the per-server lifecycle services carried only dead managed-mode surface. This collapses them to readiness/observability gates and drops the now-dead managed/strategy healthcheck branching.

Deltas

• ChromaLifecycleService (MC) + DatabaseLifecycleService (KB) — deleted startDatabase / stopDatabase / waitForHeartbeat / manageDatabase / cleanup (grep-confirmed 0 prod callers), the spawn/child_process + unused aiConfig imports, the KB chromaProcess config member, and the Observable mixin + processActive event (no listener anywhere). Kept initAsync (boot ordering, awaited by SystemLifecycleService + ChromaManager via ready()) and getDatabaseStatus (healthcheck), simplified to {running: false}.
• HealthService (MC) — dropped the database.process.managed / strategy branching. The only downstream reader consumes .running (KB Server); nothing read managed/strategy. Reports external-only now.
• Tests — rewrote the two lifecycle specs to the kept surface; removed dead aiConfig.<retired-flag> = false setup-lines across 9 specs (autoDream/autoSummarize/realTimeMemoryParsing/autoIngestFileSystem no longer exist post-#12139) + the 4 now-orphaned import aiConfig lines they left behind.

ChromaManagers needed no change — they only await <Lifecycle>.ready(), which is preserved; AC6's "ChromaManagers simplified" was already satisfied (no lifecycle coupling beyond the readiness gate).

Test Evidence

Evidence: L2 (executed) — npm run test-unit over the 12 affected spec files exits 0 with 124 passing (incl. the 51-test HealthService suite confirming the managed/strategy removal is non-breaking, and the 2 rewritten lifecycle specs).

node --check clean on all 14 changed files (disk-truth — confirms no duplicate/orphaned imports). Both pre-commit gates (check-whitespace, check-shorthand) pass. The retired-primitive guard (#12198) still passes on this branch. grep confirms 0 remaining retired-flag setup-lines + 0 orphaned aiConfig imports across test/.

Post-Merge Validation

Behaviour-preserving: the deleted methods had no callers; getDatabaseStatus keeps the running field its sole consumer reads; the healthcheck details now states "Connected to the orchestrator-managed ChromaDB instance" instead of the managed/external conditional. On merge this closes #12139 (ACs 1–5 + 7 satisfied by PRs #12197 + #12200; AC6 satisfied here).

Decision Record impact

aligned-with ADR 0003 (unified Chroma topology) — establishes the orchestrator as the sole Chroma lifecycle authority for both MCP servers; the services retain only a readiness gate.

FAIR-band: n/a — operator-directed lane (#12139 PR B).

Resolves #12139.

Authored by Claude Opus 4.8 (Claude Code, 1M context).