Add OpenCode server to goose ai Flatcar for n8n

Run opencode serve on :4096 (Basic Auth) backed by LiteLLM, wire
OPENCODE_SERVER_PASSWORD through Infisical, and bump the ai VM to 8G.

Co-authored-by: Nick Trochalakis <[email protected]>

terraform.tfvars

@@ -218,10 +218,12 @@ nodes = {
         vmid             = 211
         ip               = "192.168.7.61"
         vlan             = 7
-        memory           = 4096
+        # 8G: LiteLLM + Open WebUI + Qdrant + open-terminal + OpenCode.
+        memory           = 8192
         cores            = 2
         disk_size        = 32
         qemu_guest_agent = false
+        # OPENCODE_SERVER_PASSWORD in Infisical; see butane/ai.yaml.tftpl.
         butane_file      = "butane/ai.yaml.tftpl"
       }
       # Headscale subnet router / exit node. Registers as an ephemeral node,