chore(gates): zero clippy warnings and a buildable sandbox example on Windows

The full-workspace gates had never run on this platform: collapsible
ifs in the Windows shell probe, a same-type cast in the crash handler,
an unused AsRawHandle import, and the sandbox smoke-test example
building its unix-only body (libc, kernel enforcement) unconditionally.
The example now stubs main off-unix; formatting reflow from cargo fmt.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KSy9S31pZNWXtRZNVJ1sDf

crates/codegen/kigi-shell/src/util/config/resolve/compaction.rs

@@ -187,7 +187,10 @@ mod compaction_tool_choice_tests {
             resolve(Some("bogus"), None, Some("none")),
             CompactionToolChoice::None
         );
-        assert_eq!(resolve(Some("NONE "), None, None), CompactionToolChoice::None);
+        assert_eq!(
+            resolve(Some("NONE "), None, None),
+            CompactionToolChoice::None
+        );
     }
 }