fix: address foundation scrutiny findings

- Make CI smoke commands Windows-aware by using OS-neutral cargo run invocations
- Replace masked negative smoke checks (|| true) with explicit non-zero assertions
- Remove Cargo.lock from .gitignore and track for binary reproducibility
- Strengthen secret redaction to eliminate stable first/last character leakage
- Remove readme field from Cargo.toml that referenced a missing README.md

src/redact.rs

@@ -30,15 +30,8 @@ impl fmt::Display for Redacted {
         let len = self.0.len();
         if len == 0 {
             write!(f, "[REDACTED]")
-        } else if len <= 4 {
-            write!(f, "[REDACTED(len={})]", len)
         } else {
-            write!(
-                f,
-                "[REDACTED(len={}...{})]",
-                &self.0[..2],
-                &self.0[len - 2..]
-            )
+            write!(f, "[REDACTED(len={})]", len)
         }
     }
 }