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

Cargo.toml

@@ -4,7 +4,6 @@ version = "0.1.0"
 edition = "2024"
 description = "Cross-platform HTTPS mTLS lab/dev tunneling tool"
 license = "MIT"
-readme = "README.md"
 
 [dependencies]
 clap = { version = "4", features = ["derive"] }