v0.5.0

Architecture

Six-stage user-visible lifecycle: clarify → design → plan → implement → verify → archive.
Classification is internal and durable. TDD is an implementation strategy, not a lifecycle stage.
route and tdd exist only in v4/v5 compatibility readers.

Added

• State v6 (runtime/core/change-state.mjs): minimal revisioned state with
  updateChangeState() as the sole mutation primitive (lock → copy → mutate → validate →
  CAS → atomic write → event). No persisted ready/approved booleans; freshness is
  digest-derived.
• Handoff v2 (runtime/core/handoff-v2.mjs): canonical run transport under
  <git-common-dir>/enterprise-harness/runs/, safe across native worktrees.
• v5 → v6 migration (runtime/compat/v5-migrate.mjs, runtime/migrate-v5.mjs):
  explicit, confirmation-gated migration for active changes; archives stay read-only.
• Session and lock leases with heartbeat renewal and expiry-based recovery.
• Nine canonical skills: harness, explore-code, research-docs, design, plan,
  implement, review, verify, archive.
• Five capability agents: code-explore, doc-research, artifact-worker,
  implementer (worktree-isolated, sole product-code writer), reviewer.
• Quality loop: every stage/task requires execute → self-check → independent review → TECPC → fresh evidence.
• Native plugin layout regression smoke and v0.5 capability-surface smoke.

Changed

• Plugin assets moved to root skills/, agents/, hooks/scripts/.
• harness skill rewritten as the sole user-facing orchestrator for the six-stage lifecycle.
• Forked methodology skills return NEEDS_DECISION instead of calling AskUserQuestion.
• Hooks limited to host-boundary mechanics; agent lifecycle events are telemetry only.
• Specs rewritten: workflow, state-schema, agents-and-handoff, hooks, evidence.
• runtime/compat/ isolates all v4/v5 legacy agents, skills, and contract tests.

Removed

• .claude/rules/ auto-loaded controller rules (replaced by specs and skill methodology).
• Legacy .claude/skills/ and .claude/agents/ as plugin asset locations.
• runtime/hooks/ as hook script location (moved to hooks/scripts/).
• Legacy stage skills (harness-design, harness-plan, harness-tdd, harness-verify)
  from the canonical plugin surface (moved to runtime/compat/skills/).