mcp-config/hermes: make the gateway's context limits actually reach the clients

Folds in the in-flight local-checkout work and fixes the context accounting
on top of it. Both halves are the same bug seen from two ends: clients were
sending requests larger than the backend's window and getting hard
ContextWindowExceededError 400s, intermittently, in a way that looked like
the model or the GPU misbehaving.

Already in flight here (unchanged in intent):
  - sync.sh prefers the LOCAL CHECKOUT over re-downloading from Gitea, and
    install.sh records the checkout path so it can be found. That recording
    is load-bearing: without it sync.sh cannot find the repo, silently falls
    back to Gitea, and every local edit to opencode.gateway.json is ignored.
    Observed on this box — ~/.config/mcp-sync/source did not exist, the
    default ~/.dotfiles is not where the checkout lives, and the Gitea base
    still served models:{}.
  - the hermes custom-provider wiring.

Fixed on top:

opencode had NO context limit on ANY gateway model, not a wrong one. Two
faults compounded. /model/info 403s for a day-to-day virtual key (only
management-scoped keys may read it), which sync.sh treats as best-effort and
falls back to names-only — as designed and as commented. But the merge then
did `prov["models"] = models`, replacing the map wholesale, so limits
declared in the base config were discarded too and there was no floor left.
Base specs are now a floor that live /model/info overrides field by field:
discovery still wins where present, so this adds no drift, and a 403 no
longer strips the limits. Verified: ornith 195584/32768, the qwens
261120/32768.

hermes' model map named `qwen3-vl-30b-a3b` at 262144 — a model the gateway
stopped serving when Ornith replaced it — while ornith-1.0-35b, the model
actually on cg-1 AND the only one with a window smaller than its neighbours
(196608), had no entry at all and inherited Hermes' default. The one model
needing a lower ceiling was the one not declaring one, which is exactly the
shape that fails only once a session grows.

NOTE for other boxes: hermes reads ~/.hermes/config.yaml, which install.sh
produces by MERGING gateway.yaml. Editing gateway.yaml alone changes nothing
until install.sh re-runs — this machine's live config was patched by hand.

Not addressed here, deliberately: the gateway-side context_window_fallback
(ai-k8s-iac). It is wired but inert while cg-2 is scaled down, so preventing
the oversized request client-side is what actually works today.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FoDK4wwB1Twty5gwiriYLf

mcp-config/opencode.gateway.json

@@ -8,13 +8,36 @@
         "baseURL": "https://llm.covert-gpt.com/v1",
         "apiKey": "{env:LITELLM_KEY}"
       },
-      "models": {}
+      "models": {
+        "ornith-1.0-35b": {
+          "limit": {
+            "context": 195584,
+            "output": 32768
+          }
+        },
+        "qwen3.8-27b": {
+          "limit": {
+            "context": 261120,
+            "output": 32768
+          }
+        },
+        "qwen3-coder-next": {
+          "limit": {
+            "context": 261120,
+            "output": 32768
+          }
+        }
+      }
     }
   },
   "mcp": {
     "gitea": {
       "type": "local",
-      "command": ["npx", "-y", "gitea-mcp@0.0.10"],
+      "command": [
+        "npx",
+        "-y",
+        "gitea-mcp@0.0.10"
+      ],
       "enabled": true,
       "environment": {
         "GITEA_HOST": "https://git.nic-oconnor.com",
@@ -23,18 +46,24 @@
     },
     "proxmox": {
       "type": "local",
-      "command": ["npx", "-y", "proxmox-mcp-server@0.2.0"],
+      "command": [
+        "npx",
+        "-y",
+        "proxmox-mcp-server@0.2.0"
+      ],
       "enabled": true,
       "environment": {
         "PROXMOX_HOST": "https://prox-01.covert-cloud.com:8006",
-        "PROXMOX_TOKEN_ID": "{env:PROXMOX_MCP_TOKEN_ID}",
-        "PROXMOX_TOKEN_SECRET": "{env:PROXMOX_MCP_TOKEN_SECRET}",
+        "PROXMOX_TOKEN_ID": "{env:PROXMOX_TOKEN_ID}",
+        "PROXMOX_TOKEN_SECRET": "{env:PROXMOX_TOKEN_SECRET}",
         "PROXMOX_INSECURE_TLS": "true",
         "PVE_READONLY": "false"
       }
     }
   },
   "skills": {
-    "paths": ["{env:HOME}/.config/mcp-sync/skills"]
+    "paths": [
+      "{env:HOME}/.config/mcp-sync/skills"
+    ]
   }
 }