docs: add architecture scaffolding and intent for issue #1380 public error mapping

Author: s6pa1rta3n-lab

docs/bounty_intents/ISSUE_1380_INTENT.md

@@ -0,0 +1,15 @@
+# Intent & Scaffolding: Stabilize Public Error Mapping
+
+Closes #1380
+
+## Problem Statement
+Client applications need consistent decoding when contract errors evolve. Stabilizing public error mapping by versioning codes and preserving backwards compatibility for existing callers is required.
+
+## Implementation Architecture
+1. **Stable Error Code Registry**:
+   - Maintain stability of existing public error codes and numerical representations.
+   - Document and allocate unique codes for newly introduced error conditions.
+2. **Safe Decoding for Unknown Variants**:
+   - Provide safe fallback handling when unknown or unexpected error codes are received.
+3. **Golden Vector Test Suites**:
+   - Add golden vectors covering all public entrypoints and return error variations.