Adds three new tables for the durable LLM agent runtime:
subagent_messages — Anthropic message-block persistence.
Parallel tool_use blocks in one assistant
message live in content_blocks JSONB, not
across rows (fixes the (job_id, turn_idx, role)
misdesign codex caught in v0.13 drafting).
subagent_tool_executions — Two-phase tool ledger. INSERT pending before
execute, UPDATE complete/failed after. Replay
re-runs pending rows only if the tool is
idempotent (v1 ships only idempotent tools so
this is preventive).
subagent_rate_leases — Lease-based concurrency cap for outbound
providers (e.g. anthropic:messages). Stale
leases auto-prune on next acquire so crashed
workers can't strand capacity.
All DDL uses CREATE TABLE/INDEX IF NOT EXISTS — order-independent vs
PR #244's initSchema() reorder, and idempotent across fresh-install +
upgrade paths. Shipped in both src/schema.sql (Postgres) and
src/core/pglite-schema.ts (PGLite); schema-embedded.ts regenerated.
Migration orchestrator v0_15_0.ts (phases: schema → verify → record).
v0_14_0.ts is a no-op stub so the registry's version sequence stays
gapless (v0.14.0 shipped shell-jobs — code change, no DB migration).
10 unit tests for registry wiring, ordering, dry-run phase behavior, and
schema-embedded table presence. test/apply-migrations.test.ts updated for
the two new registry entries.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>