Initial scaffold: image/ FastAPI app, models.yaml, docs

- image/ FastAPI app: /api/status, /api/swap, /api/swap/{id}/stream, /api/test-connection
- models.yaml: 5-model catalog (qwen3-vl, gemma4, qwen36, qwen3-235b-fp8, qwen25-72b)
- README, runbook, known-issues
- Dry-run swap verified against live Spark 1 (gemma4 currently loaded)

image/entrypoint.sh

@@ -0,0 +1,20 @@
+#!/bin/sh
+set -eu
+
+# Persist ssh state on the StartOS volume (mounted at /data when packaged).
+SSH_DIR="${SSH_DIR:-/data/ssh}"
+mkdir -p "$SSH_DIR"
+chmod 700 "$SSH_DIR"
+
+if [ ! -f "$SSH_DIR/id_ed25519" ]; then
+  echo "[entrypoint] Generating ed25519 keypair for SSH to Sparks..."
+  ssh-keygen -t ed25519 -N "" -f "$SSH_DIR/id_ed25519" -C "spark-control@start9" >/dev/null
+fi
+chmod 600 "$SSH_DIR/id_ed25519"
+chmod 644 "$SSH_DIR/id_ed25519.pub"
+touch "$SSH_DIR/known_hosts" && chmod 600 "$SSH_DIR/known_hosts"
+
+export SSH_KEY_PATH="${SSH_KEY_PATH:-$SSH_DIR/id_ed25519}"
+export SSH_KNOWN_HOSTS="${SSH_KNOWN_HOSTS:-$SSH_DIR/known_hosts}"
+
+exec uvicorn app.server:app --host 0.0.0.0 --port "${BIND_PORT:-9999}"