feat(crg): add Current Grade badge anchor to READINESS.md

Adds **Current Grade:** C line before the Grade Reference section.
Grade C reflects CRG C blitz 2026-04-04 (template file, self-validated).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: hyperpolymath

READINESS.md

@@ -7,6 +7,8 @@
 **Assessed:** 2026-03-01
 **Assessor:** Jonathan D.A. Jewell
 
+**Current Grade:** C
+
 ## Grade Reference
 
 | Grade | Name                  | Release Stage      | Meaning                                              |