feat: Implement DefaultCryptoHmac for compliance-aware HMAC operations

- Added DefaultCryptoHmac class implementing ICryptoHmac interface.
- Introduced purpose-based HMAC computation methods.
- Implemented verification methods for HMACs with constant-time comparison.
- Created HmacAlgorithms and HmacPurpose classes for well-known identifiers.
- Added compliance profile support for HMAC algorithms.
- Included asynchronous methods for HMAC computation from streams.

.claude/settings.local.json

@@ -1,8 +1,13 @@
 {
   "permissions": {
     "allow": [
-      "Bash(wc:*)",
-      "Bash(sort:*)"
+      "Bash(dotnet --list-sdks:*)",
+      "Bash(winget install:*)",
+      "Bash(dotnet restore:*)",
+      "Bash(dotnet nuget:*)",
+      "Bash(csc -parse:*)",
+      "Bash(grep:*)",
+      "Bash(dotnet build:*)"
     ],
     "deny": [],
     "ask": []