refactor(docs): co-locate k8s/proxmox docs with their code + fix broken perf paths

Docs moved from docs/k8s -> k8s/docs and docs/proxmox -> proxmox/docs to sit
beside their code. Updated all cross-references (docmap, STATUS, README, AGENTS,
k8s README). Fixed SCRIPT_DIR path resolution in 3 perf scripts broken by the
reorg (deploy-check/and-fix/finish-host pointed at root/scripts instead of
perf/scripts). Registered the new top-level proxmox/ dir in all listings.

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Assisted-by: Crush:glm-5.2

k8s/README.md

@@ -42,7 +42,7 @@ kubectl get nodes
 ## Design Decisions
 
 - **k3s (not Talos):** This is a regular R&D cluster, not ITAR/classified.
-  Talos architecture is documented in [`docs/k8s/`](../docs/k8s/) for when
+  Talos architecture is documented in [`docs/`](docs/) for when
   that requirement comes online. k3s on stock Debian is simpler to operate.
 - **Tailscale-only transport:** `--node-ip`, `--advertise-address`, and
   `--tls-san` are all set to Tailscale IPs. No LAN IP appears in any node