[refactor] update Cargo.lock with new dependency additions and version bumps

crates/polyscribe-core/Cargo.toml

@@ -14,3 +14,8 @@ chrono = "0.4.41"
 libc = "0.2.175"
 whisper-rs = "0.14.3"
 indicatif = "0.17.11"
+# New: HTTP downloads + hashing
+reqwest = { version = "0.12.7", default-features = false, features = ["blocking", "rustls-tls", "gzip"] }
+sha2 = "0.10.8"
+hex = "0.4.3"
+tempfile = "3.12.0"