MAS-WP-0005-T02: SCP-1 quoted local-parts equivalent on receipt

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Assistant: claude-code
Assistant-Model: opus
Assistant-Process: 252470@bnt-lap001
Assistant-Session: ad628c8f-4be2-4979-94c9-76c7ed6f8241

workplans/MAS-WP-0005-spec-errata-v0-1-1.md

@@ -97,6 +97,11 @@ its own task.
   141 tests pass, and the reference parser agrees with all 35 bundle
   fixtures. SCP-2 text corrected: `Ticket=PR42` becomes non-canonical,
   not opaque.
+- 2026-10-18 SCP-1 done: §4 text; `mas_core.parser.unquote_local_part` and
+  `parse_received_address` (receiver side; the canonical parser stays
+  strict); the gateway now parses with them; fixture p1-040 note and
+  CHANGELOG. The end-to-end test now uses a real non-MAS recipient,
+  because `"quoted"@` is equivalent to `quoted@`. 148 tests pass.
 
 ## Reference service: case-robust ticket ids