Re-bake baseline with user config + delete dead savevm snapshot

Merged session overlay (8GB of user config: Startup folder VBS, registry auto-login, custom defaults) into the baseline qcow2 via qemu-img commit. Removed the savevm "booted" snapshot inside the qcow2 (cold-boot path no longer uses it, frees ~3.5GB of dead state). Verified end-to-end on GCP c2-standard-30: cold boot ~2-3min to MCP healthy, dynamic DNAT sidecar handles non-deterministic VM IP from dnsmasq.

data.qcow2

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:e23a5b27443ae340bc3873413ead758ee889e0867338cf53318aba458d5ce59c
-size 39413940224
+oid sha256:e06774ff31b0bb936f64ce968b0316056656957ae538937ca69ade24ef72def4
+size 47980150784