fix(manifests): fix port name length and env patch conflict in deploy (#1613)

## Summary

- **`ambient-ui-proxy` port name** (16 chars) exceeds Kubernetes'
15-char limit, causing the Service and Deployment to fail validation.
Renamed to `oauthproxy` across `ambient-ui-oauth-patch.yaml`,
`ambient-ui-service-patch.yaml`, and `ambient-ui-route.yaml`.
- **`GITHUB_CALLBACK_URL` env conflict** —
`frontend-github-callback-patch.yaml` used JSON Patch `op: add` which
unconditionally appends to the env array. On re-apply against a live
cluster that already had the env var set, Kubernetes ended up with
`env[7]` containing both `value` and `valueFrom`, which it rejects.
Fixed by moving `GITHUB_CALLBACK_URL` into the base
`frontend-deployment.yaml` (strategic merge patch deduplication handles
updates cleanly) and removing the patch file entirely.

Fixes the failing `deploy-to-openshift` job run
[#26603107854](https://github.com/ambient-code/platform/actions/runs/26603107854).

## Test plan
- [ ] `kustomize build components/manifests/overlays/production`
produces no errors
- [ ] All port references to `ambient-ui-proxy` renamed to `oauthproxy`
(≤15 chars)
- [ ] `GITHUB_CALLBACK_URL` appears in frontend env with only
`valueFrom` (no `value` field)
- [ ] `deploy-to-openshift` job passes on merge to main

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: jsell-rh

components/manifests/base/core/frontend-deployment.yaml

@@ -44,6 +44,12 @@ spec:
               name: unleash-credentials
               key: client-api-token
               optional: true
+        - name: GITHUB_CALLBACK_URL
+          valueFrom:
+            configMapKeyRef:
+              name: frontend-config
+              key: github-callback-url
+              optional: true
         resources:
           requests:
             cpu: 100m

components/manifests/overlays/production/ambient-ui-oauth-patch.yaml

@@ -39,18 +39,18 @@ spec:
         - --skip-auth-regex=^/metrics
         ports:
         - containerPort: 8443
-          name: ambient-ui-proxy
+          name: oauthproxy
         livenessProbe:
           httpGet:
             path: /oauth/healthz
-            port: ambient-ui-proxy
+            port: oauthproxy
             scheme: HTTP
           initialDelaySeconds: 30
           periodSeconds: 5
         readinessProbe:
           httpGet:
             path: /oauth/healthz
-            port: ambient-ui-proxy
+            port: oauthproxy
             scheme: HTTP
           initialDelaySeconds: 5
           periodSeconds: 5

components/manifests/overlays/production/ambient-ui-route.yaml

@@ -10,7 +10,7 @@ spec:
     name: ambient-ui-service
     weight: 100
   port:
-    targetPort: ambient-ui-proxy
+    targetPort: oauthproxy
   tls:
     termination: edge
     insecureEdgeTerminationPolicy: Redirect

components/manifests/overlays/production/ambient-ui-service-patch.yaml

@@ -7,6 +7,6 @@ metadata:
 spec:
   ports:
   - port: 8443
-    targetPort: ambient-ui-proxy
+    targetPort: oauthproxy
     protocol: TCP
-    name: ambient-ui-proxy
+    name: oauthproxy

components/manifests/overlays/production/frontend-github-callback-patch.yaml

@@ -68,13 +68,6 @@ patches:
     kind: Service
     name: ambient-ui-service
     version: v1
-- path: frontend-github-callback-patch.yaml
-  target:
-    group: apps
-    kind: Deployment
-    name: frontend
-    version: v1
-
 # Production images
 images:
 - name: quay.io/ambient_code/vteam_api_server:latest