docs(k8s-proxy): use ns.deployment form in branch-merge example (#860)

The `keploy cloud branch-merge` CLI flag is `--app`, which accepts
either a UUID or a `namespace.deployment` identifier (same form
`keploy upload test-set` and `keploy cloud replay` use for proxy
apps). The previous example used `<app-id>` as the placeholder,
implying UUID-only; switch to `<namespace>.<deployment>` so the
k8s-proxy form is the headline example, and add a short note
that both forms are accepted.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: charankamarapu

versioned_docs/version-4.0.0/quickstart/k8s-proxy-developer-workflow.md

@@ -193,10 +193,12 @@ jobs:
           KEPLOY_API_KEY: ${{ secrets.KEPLOY_API_KEY }}
         run: |
           keploy cloud branch-merge \
-            --app <app-id> \
+            --app <namespace>.<deployment> \
             --branch ${{ github.head_ref }}
 ```
 
+`--app` accepts either a `namespace.deployment` identifier (k8s-proxy apps, e.g. `prod.orders`) or a raw app UUID (non-proxy apps). The same form you use for `keploy upload test-set` and `keploy cloud replay` works here.
+
 `keploy cloud branch-merge` is idempotent—running it twice on an already-merged branch is a no-op. If the PR was closed without merging, the `if:` guard above keeps the job from firing.
 
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