Chore: Renumber unreleased release from 3.7.0 to 3.6.12.

The pending TaxJar response-cache work is retargeted from the 3.7.0 minor
to the 3.6.x patch line. Update the unreleased changelog and readme
headings, and move the five @SInCE stamps on the new cache-normalization
helpers so they document the version that will actually ship.

Author: bartech

changelog.txt

@@ -1,6 +1,6 @@
 *** WooCommerce Tax Changelog ***
 
-= 3.7.0 - 2026-xx-xx =
+= 3.6.12 - 2026-xx-xx =
 * Tweak - Reduce redundant TaxJar API calls by matching cached tax responses across the cart and order paths and ignoring irrelevant formatting differences.
 
 = 3.6.11 - 2026-08-05 =

classes/class-wc-connect-taxjar-integration.php

@@ -1114,7 +1114,7 @@ protected function get_line_item( $id, $line_items ) {
 	 * identical lines — an order can legitimately hold the same product twice at the
 	 * same price — distinct, so neither loses its rate.
 	 *
-	 * @since 3.7.0
+	 * @since 3.6.12
 	 *
 	 * @param array $line_items Line items whose 'id' is currently the bare product ID.
 	 *
@@ -1156,7 +1156,7 @@ private function assign_canonical_line_item_ids( array $line_items ): array {
 	 * cache keys and line item fingerprints — never to build the request sent to
 	 * TaxJar, which keeps the merchant's values verbatim.
 	 *
-	 * @since 3.7.0
+	 * @since 3.6.12
 	 *
 	 * @param mixed $value Value to normalize.
 	 *
@@ -1186,7 +1186,7 @@ private function normalize_cache_string( $value ): string {
 	 * silently reinterpreted — notably ZIP codes, where "01234" must never become
 	 * "1234".
 	 *
-	 * @since 3.7.0
+	 * @since 3.6.12
 	 *
 	 * @param mixed $value Value to normalize.
 	 *
@@ -1223,7 +1223,7 @@ private function normalize_cache_number( $value ): string {
 	 *
 	 * Only the cache key is derived from this. The body sent to TaxJar is untouched.
 	 *
-	 * @since 3.7.0
+	 * @since 3.6.12
 	 *
 	 * @param string $json Encoded TaxJar request body.
 	 *
@@ -1246,7 +1246,7 @@ private function get_cache_signature( $json ): string {
 	 * value, because several address fields hold digit-only strings that must keep
 	 * their exact form (a leading-zero ZIP above all).
 	 *
-	 * @since 3.7.0
+	 * @since 3.6.12
 	 *
 	 * @param mixed  $value Value to canonicalize.
 	 * @param string $key   Key the value was found under.

readme.txt

@@ -70,7 +70,7 @@ This plugin relies on the following external services:
 
 == Changelog ==
 
-= 3.7.0 - 2026-xx-xx =
+= 3.6.12 - 2026-xx-xx =
 * Tweak - Reduce redundant TaxJar API calls by matching cached tax responses across the cart and order paths and ignoring irrelevant formatting differences.
 
 = 3.6.11 - 2026-08-05 =