dead and incorrect test assertions

[cachebag]

several tests have assertions that don't test what they claim to.

irrefutable pattern in bt_caps assertion

api/models/tests.rs:519:

assert!(matches!(device.bt_caps, _role));

_role is an irrefutable catch-all pattern — this always passes regardless of bt_caps value. should be something like:

assert_eq!(device.bt_caps, role);

forget tests pass for the wrong reason

test_forget_nonexistent_network (integration_test.rs:547-565) — uses a 35-byte ssid ("__NONEXISTENT_TEST_SSID_TO_FORGET__") which exceeds the 32-byte ssid limit, so validate_ssid fails before reaching the "no saved connection" path. the test passes, but not for the reason it claims.

forget_returns_no_saved_connection_error (integration_test.rs:792-816) — expects ConnectionError::NoSavedConnection, but forget is documented to return Ok(()) when nothing matches. the Ok(_) branch just prints a message and doesn't actually fail.

test_forget_nonexistent_vpn (integration_test.rs:964-991) — comment says forgetting should "return error" but asserts result.is_ok(). internally inconsistent.

validation_test.rs is largely placeholder

tests/validation_test.rs uses catch_unwind with empty bodies and doesn't actually call the validation functions. real validation coverage lives in validation.rs's #[cfg(test)] module.

[cachebag]

Done in #505