bump to v0.2.0: complete provider implementation with live-tested DNS record types

- DYNU_API_KEY env var fallback in provider config
- dynu_domain resource: add 9 computed attributes (unicode_name, ipv4/ipv6 flags,
  wildcard aliases, allow_zone_transfer, dnssec, created_on, updated_on)
- dynu_dns_records data source: add 6 type-specific fields (priority, weight,
  port, flags, tag, value)
- Fix normalizeRecordContentForState for MX/SRV/NS/PTR (read host field) and CAA
  (read value field) to avoid plan/state inconsistency
- Allow underscore-prefixed DNS labels in hostname validator (RFC 2782 SRV)
- Preserve plan/state hostname across create/update/read to prevent inconsistent
  result errors when API returns full FQDN for node_name-style records
- Update all version references from 0.1.0 to 0.2.0

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LFZyrmtKsezBwFWGTWsb2y

internal/provider/resource_domain_integration_test.go

@@ -34,6 +34,15 @@ func TestIntegrationResourceDomainLifecycleAndImport(t *testing.T) {
 	if state.ID.ValueInt64() == 0 {
 		t.Fatal("expected created id")
 	}
+	if state.State.IsNull() || state.State.IsUnknown() {
+		t.Fatal("expected state attribute to be populated after create")
+	}
+	if state.UnicodeName.IsNull() || state.UnicodeName.IsUnknown() {
+		t.Fatal("expected unicode_name to be populated after create")
+	}
+	if state.DNSSEC.IsNull() || state.DNSSEC.IsUnknown() {
+		t.Fatal("expected dnssec to be a known bool after create")
+	}
 
 	state.TTL = types.Int64Value(300)
 	plan = tfsdk.Plan{Schema: schemaResp.Schema}