* feat(e2e): enable mTLS for Podman compute driver e2e harness
The Podman driver already supported mTLS certificate injection into
sandbox containers, but the e2e test harness explicitly blocked HTTPS
and ran plaintext-only gateways. Generate ephemeral PKI (CA, server,
client certs) with host.containers.internal in the server SANs, wire
guest_tls_* paths into the TOML config, replace --disable-tls with
--tls-cert/--tls-key/--tls-client-ca, and switch to mTLS gateway
registration. The health check remains on the plaintext health port.
Closes#1428
* refactor(e2e): extract shared PKI generation into gateway-common.sh
The Docker and Podman e2e scripts had near-identical 35-line PKI
generation blocks differing only in the host-gateway SAN. Extract
into e2e_generate_pki(pki_dir, host_alias) in gateway-common.sh,
which also eliminates the cd/cd pattern by using absolute paths
throughout.
* refactor(e2e): use generate-certs instead of raw openssl for PKI
Replace the hand-rolled openssl PKI generation in e2e_generate_pki()
with the gateway's built-in generate-certs --output-dir command. This
uses the same PKI generation as production deployments (Helm and RPM).
The helper now takes the gateway binary path and passes extra SANs
via --server-san (host.openshell.internal always, plus the driver's
host alias for Podman). The default SAN list already includes
host.docker.internal and localhost.
Update all cert path references to match the generate-certs output
layout (server/tls.{crt,key}, client/tls.{crt,key}) and remove the
openssl preflight checks from both gateway scripts.
Taylor Mutch