phase 1: Go foundation — module, migrations, domain, seed ingest

Core deliverables:
- Go module github.com/dtoro/oikos (Go 1.26.3)
- cmd/oikos: single binary with role subcommands (migrate, seed, export)
- 6 SQL migrations: ontology meta-schema, entity instances (UUID+slug,
  blast_radius recursive function), operations (signals/checks/approvals),
  cognition (classifications/executions/feedback/patterns/skills), policy,
  observability (TimescaleDB hypertables + CAGGs + retention)
- Domain layer: entity, signal, execution, classification, pattern, skill,
  approval, check types + 11 sentinel errors + lifecycle state machines
- DB layer: pgx pool, SQL splitter (handles 94436 and -- comments), migration
  runner, seed ingest (ontology+inventory+policy) with content-hash dedup
- Config: env-based with defaults, secrets redaction
- Observability: slog JSON logger with debug mode
- Infrastructure: Makefile, docker-compose.yml, multi-stage Dockerfile
  (distroless, CGO_ENABLED=0)

Verified end-to-end against timescale/timescaledb:2.17.2-pg16:
- 6 migrations applied (65 SQL statements)
- Seeds ingested: 6 lifecycles, 59 entity types, 46 relationship types,
  111 entities, 144 relationships, 4 risk classes, 27 approval rules,
  9 autonomy settings
- Idempotent: second seed run is a no-op (content hash matches)

Bugs fixed during implementation:
- TimescaleDB CAGGs can't run in a transaction -> splitSQL() executes
  statements individually
- Semicolons in -- comments treated as separators -> comment handling
- YAML keys source/target didn't match code's source_type/target_type
- yaml.Marshal produced YAML for JSONB columns -> json.Marshal

internal/domain/execution.go

@@ -0,0 +1,64 @@
+package domain
+
+import "time"
+
+// Classification persists every autonomous decision the classifier makes (SA5).
+// This is the audit trail for "why did the OS auto-act / escalate?"
+type Classification struct {
+	EntityID         UUID
+	SignalEntityID   UUID
+	TargetEntityID   UUID
+	Action           string
+	RecommendedAction map[string]any
+	RiskClass        string
+	Route            string
+	BlastRadius      []UUID
+	PatternConfidence float64
+	SkillID          UUID
+	AutonomyCheck    string
+	Reasoning        map[string]any
+	CorrelationID    string
+	CreatedAt        time.Time
+}
+
+// Classification routes.
+const (
+	RouteAutoAct   = "auto-act"
+	RouteEscalate  = "escalate"
+	RouteHold      = "hold"
+)
+
+// Execution is a detailed record of one action the OS performed.
+type Execution struct {
+	EntityID         UUID
+	ClassificationID UUID
+	SignalEntityID   UUID
+	TargetEntityID   UUID
+	Action           string
+	RiskClass        string
+	ApprovalID       UUID
+	AgentID          UUID
+	SkillID          UUID
+	SkillVersion     int
+	Status           string
+	Result           map[string]any
+	DurationMs       int
+	Verified         bool
+	CorrelationID    string
+	StartedAt        *time.Time
+	CompletedAt      *time.Time
+	CreatedAt        time.Time
+}
+
+// Execution lifecycle states.
+const (
+	ExecProposed    = "proposed"
+	ExecApproved    = "approved"
+	ExecExecuting   = "executing"
+	ExecVerified    = "verified"
+	ExecFailed      = "failed"
+	ExecTimedOut    = "timed-out"
+	ExecRolledBack  = "rolled-back"
+	ExecCancelled   = "cancelled"
+	ExecExpired     = "expired"
+)