Remove bufpool references and unused imports, optimize memory operations.

- Removed `bufpool` usage throughout `tag`, `tags`, and `event` packages for memory efficiency.
- Replaced in-place buffer modifications with independent, deep-copied allocations to prevent unintended mutations.
- Added new `Clone` method for deep copying `event.E`.
- Ensured valid JSON emission for nil `Tags` in `event` marshaling.
- Introduced `cmd/stresstest` for relay stress-testing with detailed workload generation and query simulation.

pkg/encoders/text/helpers.go

@@ -94,7 +94,10 @@ func UnmarshalQuoted(b []byte) (content, rem []byte, err error) {
 			if !escaping {
 				rem = rem[1:]
 				content = content[:contentLen]
-				content = NostrUnescape(content)
+				// Create a copy of the content to avoid corrupting the original input buffer
+				contentCopy := make([]byte, len(content))
+				copy(contentCopy, content)
+				content = NostrUnescape(contentCopy)
 				return
 			}
 			contentLen++