fix(audit): redact camelCase toolResult and toolArguments in audit trail (#329)

Tool results and arguments were only redacted under snake_case
tool_result/tool_arguments, but audit payloads also carry them as
toolResult/toolArguments (direct MCP and computer tool calls). The
normalized check fell through because the set lacked the stripped
forms toolresult/toolarguments, so plaintext secrets leaked into
audit_events.payload.

Add the two missing normalized keys so both spellings are covered.
Verified with redactAuditPayload unit probes: snake, camel, nested,
and upper-case variants now all return [REDACTED].

Author: Ayush7614

server/src/audit.ts

@@ -29,7 +29,9 @@ const sensitiveKeys = new Set([
   "token",
   "tokens",
   "tool_arguments",
+  "toolarguments",
   "tool_result",
+  "toolresult",
 ]);
 
 export const auditEventTypes = [