refactor: make SSH additive boolean, add ide=none

SSH is now a standalone `ssh: true/false` value that starts sshd on
port 22 *in addition to* whatever IDE is running, rather than replacing
it. The `ide` value loses the `ssh` option and gains `none` (keep
container alive with no GUI IDE, useful when ssh: true is the only
access method).

- chart/values.yaml: replace `ide: ssh` with `ssh: false` boolean
- chart/templates/deployment.yaml: expose port 22 when ssh=true,
  port 5800 when ide!=none; probes use HTTP (VNC) or TCP socket (SSH-only)
- chart/templates/service.yaml: include both ports when both enabled
- scripts/cont-init-sshd.sh: check SSH=true instead of IDE=ssh
- scripts/startapp.sh: add ide=none case (sleep infinity), drop ssh case
- chart/Chart.yaml: bump to 0.1.6
- README.md: update IDE choice and SSH access docs

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

scripts/cont-init-sshd.sh

@@ -1,9 +1,9 @@
 #!/bin/sh
-# Start OpenSSH server for SSH IDE mode.
+# Start OpenSSH server when SSH=true.
 # Runs as root during container initialisation (cont-init.d).
-[ "${IDE:-vscode}" = "ssh" ] || exit 0
+[ "${SSH:-false}" = "true" ] || exit 0
 
-echo "=== SSH IDE mode: starting sshd ==="
+echo "=== SSH enabled: starting sshd ==="
 
 # Generate host keys if missing (first boot or ephemeral /etc/ssh)
 ssh-keygen -A 2>/dev/null || true

scripts/startapp.sh

@@ -23,8 +23,8 @@ case "$IDE" in
         echo "Opening Google Antigravity in: $WORKSPACE_DIR"
         exec antigravity --new-window --wait "$WORKSPACE_DIR"
         ;;
-    ssh)
-        echo "SSH mode: sshd started by cont-init. Keeping container alive."
+    none)
+        echo "IDE=none: no IDE launched, keeping container alive."
         exec sleep infinity
         ;;
     *)