Handle deferred closure dispatch to avoid false positives

[Codex]

Deferred dispatch inside an Enabled guard was flagged as undispatched even though the closure called Msg on the captured event.

• Problem: a defer func() { evt.Msg(...) }() guarded by if evt := log.Debug(); evt.Enabled() incorrectly triggered “must be dispatched” diagnostics.
• Analyzer: track MakeClosure free vars and bindings, deleting captured zerolog events when dispatch occurs inside the closure; also unwrap unary ops when resolving event roots.
• Tests: add regression covering the guarded-defer pattern to ensure the analyzer accepts it.

Example:

if evt := log.Debug(); evt.Enabled() {
	defer func() {
		evt.Msg("server stopped")
	}()
}

Original prompt

---

This section details on the original issue you should resolve

<issue_title>False positive with defer</issue_title>
<issue_description>```go
package chunkstore

import "github.com/rs/zerolog/log"

func main() {
if evt := log.Debug(); evt.Enabled() {
defer func() {
evt.Msg("Server stopped")
}()
}
}

```shell
$ golangci-lint run -Ezerologlint
main.go:6:21: must be dispatched by Msg or Send method (zerologlint)
	if evt := log.Debug(); evt.Enabled() {
	                   ^
```</issue_description>

## Comments on the Issue (you are @codex[agent] in this section)

<comments>
</comments>

• Fixes False positive with defer #20