Add: building a Debian 13 VM on Proxmox for running agents

A machine-followable build guide -- free VMID out of the shared container/VM ID space, disk on a redundant ZFS array rather than the boot pool, official cloud image imported instead of an installer, cloud-init for user, keys and static address. Every step carries its verification command and the output that means correct.

Written against Proxmox VE 9.2.10 and Debian 13 trixie, built and verified 2026-08-30. Commands were extracted from the build transcript rather than recalled, and section 17 records where the guide's original brief was wrong.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Home.md

@@ -40,6 +40,21 @@ built, so you can decide what to take and what to leave.
   thing they guard, and what one prose rule did when it became an enforced
   check.
 
+- **[Building a Debian VM on Proxmox, for agents](Building-a-Debian-VM-on-Proxmox-for-agents)**
+  -- provisioning a full VM, not an LXC container, on a Proxmox VE node: picking
+  a free VMID out of an ID space that containers and VMs silently share, putting
+  the disk on a redundant ZFS array rather than the boot pool, importing an
+  official cloud image instead of sitting through an installer, and driving the
+  whole build through cloud-init so the machine comes up already reachable by
+  key. Every step carries its verification command and the output that means
+  "correct". The traps are the point: a guest agent Debian installs but does not
+  start, a pool that turns out to be thick-provisioned and reserves the entire
+  disk, a network assumed to be a /24 that was a flat /16 with no DHCP on it,
+  and a rename that changes the hypervisor's label but not the guest's own
+  hostname. Ends with a section recording where the guide's original brief was
+  wrong, because the commands were extracted from the build transcript rather
+  than recalled afterwards.
+
 ## Conventions on this wiki
 
 Each page says what it was verified against and when -- a version number, a