phase 1 review fixes: dedup edges, real export, validation, tests

Review of aa2ca0a found and fixed:
- re-ingest duplicated ALL edges (upsert conflicted on valid_from=now(),
  never fired) — migration 007 dedupes + partial unique index on current
  edges; upsert now targets it. Regression-tested.
- export was a stub that overwrote seeds/*.yaml with 11-byte "version: 1"
  files — implemented real deterministic export (ontology/inventory/policy,
  cognition-layer excluded); round-trip is byte-stable (tested)
- DB password leaked in startup logs (slog JSON bypasses String()) —
  Config now implements slog.LogValuer; regression-tested
- docker-compose had literal '***' as DB password — env-interpolated
- uuid.New() (v4) → uuid.NewV7() per ADR-0005
- no ontology validation on ingest — internal/ontology TypeTree: abstract
  instantiation rejected, relationship endpoints hierarchy-validated,
  cardinality enforced in-transaction, lifecycle states checked, default
  state applied (Phase 1 gate items, R3-1)
- getOrCreateEntityID swallowed non-ErrNoRows errors
- migration runner now holds a session advisory lock on one connection
- Makefile: hardcoded /opt/homebrew/bin/go → go; test-db target

Tests: 4 unit suites + 7 integration tests (env-guarded, throwaway DB per
run): migrate idempotent, seed idempotent + no dup edges, abstract/edge/
cardinality rejection, blast_radius cycle termination, export round-trip.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Makefile

@@ -1,7 +1,7 @@
 .PHONY: build test lint generate dev migrate seed export clean
 
 BINARY := oikos
-GO := /opt/homebrew/bin/go
+GO ?= go
 
 build:
 	$(GO) build -o $(BINARY) -tags timetzdata ./cmd/oikos
@@ -9,6 +9,13 @@ build:
 test:
 	$(GO) test -race -cover ./...
 
+# Integration tests against the compose Postgres (starts it if needed)
+test-db:
+	docker compose up -d postgres
+	@sleep 3
+	OIKOS_TEST_DATABASE_URL="postgres://oikos:$${OIKOS_DB_PASSWORD:-oikos_dev}@localhost:5432/oikos?sslmode=disable" \
+		$(GO) test -race -count=1 ./internal/db/
+
 lint:
 	$(GO) vet ./...
 	@command -v golangci-lint >/dev/null 2>&1 && golangci-lint run || echo "golangci-lint not installed, skipping"