Revert "feature: Configurable Webhook HMAC Signature Verification (#1549)"

This reverts commit 7d8a4c2.

Author: Claude Sonnet 4.5

.changeset/configurable-webhook-signatures-core.md

@@ -0,0 +1,16 @@
+{
+  "permissions": {
+    "allow": [
+      "WebFetch(domain:docs.inkeep.com)",
+      "WebFetch(domain:a2a-protocol.org)",
+      "Bash(pnpm:*)",
+      "WebFetch(domain:docs.docker.com)",
+      "WebFetch(domain:raw.githubusercontent.com)",
+      "WebSearch"
+    ]
+  },
+  "sandbox": {
+    "enabled": true,
+    "autoAllowBashIfSandboxed": true
+  }
+}

.changeset/configurable-webhook-signatures-sdk.md

@@ -89,7 +89,3 @@ progress.txt
 
 # PID files from auto-started services
 .pid
-
-.ralph-archives/
-
-.claude/settings.local.json

.changeset/configurable-webhook-signatures-ui.md

@@ -0,0 +1 @@
+feat/PRD-5609-keytar