docs(express): update canonicalAddress API docs

- BSV supports base58 only (not cashaddr)
- Update parameter descriptions (cashaddr = BCH-only)
- Add BSV deprecation

TICKET: WP-6972

Author: Marzooqa

modules/express/src/typedRoutes/api/v2/canonicalAddress.ts

@@ -14,9 +14,9 @@ export const CanonicalAddressRequestParams = {
  * Request body for canonical address conversion
  */
 export const CanonicalAddressRequestBody = {
-  /** Address to canonicalize - can be in any supported format (base58, cashaddr, etc.) */
+  /** Address to canonicalize - can be in any supported format (base58, cashaddr for BCH only, etc.) */
   address: t.string,
-  /** Desired address format: 'base58' or 'cashaddr' (BCH/BSV: defaults to 'base58', LTC: ignored as addresses are returned unchanged) */
+  /** Desired address format: 'base58' (supported by BCH, BSV, LTC) or 'cashaddr' (supported by BCH only). Defaults to 'base58'. LTC ignores this parameter. */
   version: optional(t.union([t.literal('base58'), t.literal('cashaddr')])),
   /** @deprecated Use version instead. Fallback parameter for version. */
   scriptHashVersion: optional(t.union([t.literal('base58'), t.literal('cashaddr')])),
@@ -30,18 +30,23 @@ export const CanonicalAddressRequestBody = {
  *
  * **Supported Coins:**
  * - **Bitcoin Cash (BCH/TBCH)**: Converts between base58 and cashaddr formats
- * - **Bitcoin SV (BSV/TBSV)**: Converts between base58 and cashaddr formats
+ * - **Bitcoin SV (BSV/TBSV)**: Supports base58 format only (cashaddr not supported)
  * - **Litecoin (LTC/TLTC)**: Returns address unchanged (included for API consistency)
  *
  * **Address Formats:**
  * - **base58**: Traditional Bitcoin-style addresses (e.g., '1BpEi6DfDAUFd7GtittLSdBeYJvcoaVggu', '3CWFddi6m4ndiGyKqzYvsFYagqDLPVMTzC')
  * - **cashaddr**: Bitcoin Cash address format with network prefix (e.g., 'bitcoincash:qpm2qsznhks23z7629mms6s4cwef74vcwvy22gdx6a')
  *
- * **BCH/BSV Behavior:**
+ * **BCH Behavior:**
  * - version='base58': Converts any input format to base58 canonical format
  * - version='cashaddr': Converts any input format to cashaddr format (adds network prefix if missing)
  * - Default (no version): Converts to base58 format
  *
+ * **BSV Behavior (Deprecated):**
+ * - version='base58': Converts address to base58 canonical format
+ * - version='cashaddr': Not supported - will return error "unsupported address format cashaddr for network bitcoinsv"
+ * - Default (no version): Converts to base58 format
+ *
  * **LTC Behavior:**
  * - Returns the input address unchanged regardless of version parameter
  * - Included for API consistency but performs no transformation