Revert stream-binding approach: merge GET into the single MCP route instead

The second ai-mcp-proxy binding (added to fix the GET/SSE 502 loop)
created a second runtime plugin instance with the same tool config,
which ai-mcp-proxy's own duplicate-name detection caught: all three
tools (list-customers/get-customer/create-customer) fell back to
auto-generated names across both instances. Confirmed via dataplane
pod logs right after applying the previous fix.

Real fix: one KongRoute for all three MCP HTTP methods (GET/POST/
DELETE) instead of two, one ai-mcp-proxy binding instead of two.
ai-mcp-proxy already tolerates multi-method routes (same "skips
method selection" notice the existing POST+DELETE route already
produces) — extending to GET is the same class of thing, not new
risk, and there is now exactly one plugin instance so no duplicate
tool names.

kong/mcp/pluginbindings.yaml

@@ -34,37 +34,6 @@ spec:
       kind: KongRoute
       name: ${NAME}-customers-mcp
 ---
-# Also bind to the GET/-stream route, not just the POST/DELETE one above.
-# Without this, GET requests never reach ai-mcp-proxy at all and fall
-# through to the KongService's own upstream target — which is
-# ${REST_HOSTNAME} (Kong's own external hostname, mcp/service.yaml), so an
-# unintercepted GET loops back into the Gateway and grows response headers
-# on every pass until nginx rejects it ("upstream sent too big header",
-# 502) — confirmed 2026-08-23 via customers dataplane pod logs (28
-# occurrences) while debugging a LibreChat connection failure specific to
-# customers-mcp. catalog-mcp has the identical gap (checked: its
-# ai-mcp-proxy-binding also targets only the non-stream route) but happens
-# to fail as a harmless 405 there instead of looping — not fixed here,
-# flagged in STATUS.md, don't assume catalog's GET stream actually works
-# just because nothing broke loudly.
-apiVersion: configuration.konghq.com/v1alpha1
-kind: KongPluginBinding
-metadata:
-  name: ${NAME}-customers-mcp-ai-mcp-proxy-stream-binding
-  namespace: ${NAMESPACE}
-spec:
-  controlPlaneRef:
-    type: konnectNamespacedRef
-    konnectNamespacedRef:
-      name: ${CONTROL_PLANE_REF_NAME}
-  pluginRef:
-    name: ${NAME}-customers-mcp-ai-mcp-proxy
-  targets:
-    routeRef:
-      group: configuration.konghq.com
-      kind: KongRoute
-      name: ${NAME}-customers-mcp-stream
----
 apiVersion: configuration.konghq.com/v1alpha1
 kind: KongPluginBinding
 metadata: