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/pattern.go

@@ -0,0 +1,76 @@
+package domain
+
+import "time"
+
+// Feedback records what was learned from an execution.
+type Feedback struct {
+	EntityID              UUID
+	ExecutionID           UUID
+	Outcome               string
+	Observation           string
+	Lesson                string
+	UnexpectedSideEffects []string
+	Tags                  []string
+	CreatedAt             time.Time
+}
+
+// Feedback outcomes.
+const (
+	OutcomeSuccess    = "success"
+	OutcomeFailure    = "failure"
+	OutcomePartial    = "partial"
+	OutcomeUnexpected = "unexpected"
+)
+
+// Pattern is a generalized rule extracted from accumulated feedback.
+type Pattern struct {
+	EntityID         UUID
+	AppliesType      string
+	Action           string
+	Pattern          string
+	Confidence       float64
+	EvidenceCount    int
+	SuccessCount     int
+	FailureCount     int
+	Status           string
+	Quarantined      bool
+	Version          int
+	LastValidatedAt  *time.Time
+	CreatedAt        time.Time
+}
+
+// Pattern lifecycle states.
+const (
+	PatternHypothesized = "hypothesized"
+	PatternValidated    = "validated"
+	PatternActive       = "active"
+	PatternDeprecated   = "deprecated"
+	PatternInvalidated  = "invalidated"
+)
+
+// Skill is a codified procedure refined through validated patterns.
+type Skill struct {
+	EntityID     UUID
+	Version      int
+	Name         string
+	Procedure    map[string]any
+	AppliesType  string
+	Action       string
+	PatternIDs   []UUID
+	Status       string
+	SuccessRate  float64
+	ChangedBy    UUID
+	ChangeReason string
+	LastUsedAt   *time.Time
+	CreatedAt    time.Time
+}
+
+// Skill lifecycle states.
+const (
+	SkillDrafted   = "drafted"
+	SkillTested    = "tested"
+	SkillActive    = "active"
+	SkillRefined   = "refined"
+	SkillDeprecated = "deprecated"
+	SkillFailed    = "failed"
+)