MCP: serve tools from the API process over Streamable HTTP at /mcp

- netx_api/mcp_remote: ops / topology / bizMonitor tools, Bearer auth,
  per-tool RBAC filtering, ?groups= filter, readOnlyHint and group meta.
- Mount the official MCP Streamable HTTP app at /mcp (stateless);
  AuthAuditMiddleware is pure ASGI and skips /mcp.
- Let uvicorn chunk MCP responses; some Windows LSPs rewrite
  Content-Length replies on */mcp* paths into broken chunked framing.
- NETX_MCP_ALLOWED_HOSTS opts into DNS-rebinding checks (off by default
  so LAN and reverse-proxy hosts work; Bearer is the gate).
- Remove the three stdio Python MCP packages; tests moved to /mcp,
  including real-TCP framing regressions.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

netx_api/mcp_remote/topology/layout_ops/channel_metro.py

@@ -0,0 +1,72 @@
+"""channel_metro: corridor skeleton → core beam pin → channel soft petals.
+
+Composes proven atoms for giant star / core_bar canvases where ~90% of
+nodes sit on deg≤2 corridors.
+"""
+
+from __future__ import annotations
+
+from netx_api.mcp_remote.topology.layout_metrics import count_edge_crossings
+from netx_api.mcp_remote.topology.layout_ops.channels import extract_channels
+from netx_api.mcp_remote.topology.layout_ops.hotspots import fix_overlaps_local
+from netx_api.mcp_remote.topology.layout_ops.pin_beam import pin_beam_rigid
+from netx_api.mcp_remote.topology.layout_ops.ring_faces import eject_intruders, extract_ring_faces
+from netx_api.mcp_remote.topology.layout_ops.skeleton import build_skeleton
+from netx_api.mcp_remote.topology.layout_ops.soft_petals import soft_petals_greedy
+from netx_api.mcp_remote.topology.layout_ops.state import LayoutParams, LayoutState, OpResult
+from netx_api.mcp_remote.topology.layout_ops.transforms import normalize_origin
+
+
+def build_channel_metro_skeleton(
+    state: LayoutState, params: LayoutParams | None = None
+) -> OpResult:
+    """Compose: Tutte skeleton → pin_beam → soft_petals → ring eject → fix ov."""
+    params = params or LayoutParams()
+    channels = extract_channels(state)
+    rings = extract_ring_faces(state, max_len=5, max_cycles=40)
+
+    sk = build_skeleton(state, params)
+    st = sk.state
+
+    beam = pin_beam_rigid(st, params)
+    st = beam.state
+
+    petals = soft_petals_greedy(st, params)
+    st = petals.state
+
+    cores = {n for n, ly in st.layers.items() if ly == "core"}
+    aggs = {n for n, ly in st.layers.items() if ly == "agg"}
+    st.positions = eject_intruders(
+        dict(st.positions),
+        rings,
+        push=max(params.side * 0.25, 36.0),
+        protected=cores | aggs,
+    )
+
+    st = fix_overlaps_local(st, params).state
+    st = normalize_origin(st, params).state
+
+    cross = count_edge_crossings(st.positions, st.links)
+    st.meta = dict(st.meta or {})
+    st.meta["rings_mode"] = "channel_metro"
+    st.meta["channel_metro"] = {
+        "channels": len(channels),
+        "rings": len(rings),
+        "pin_beam": beam.note,
+        "soft_petals": petals.note,
+        "crossings": cross,
+        "skeleton": sk.note,
+    }
+    return OpResult(
+        state=st,
+        moved=set(st.positions.keys()),
+        op="build_channel_metro_skeleton",
+        params={
+            "channel_count": len(channels),
+            "ring_count": len(rings),
+            "crossings": cross,
+            "pin_beam": beam.params,
+            "soft_petals": petals.params,
+        },
+        note=f"channel_metro ch={len(channels)} {beam.note}; {petals.note} x={cross}",
+    )