MCP: add bizMonitor server, align ops/topology tools, harden CLI exec

- New packages/netx-bizmonitor-mcp: 8 read-only cutover/biz-state tools
  mirroring the netxops bizMonitor group.
- Align netx-mcp (15) and netx-topology-mcp (16) with backend HTTP
  contracts; surface partial batch failures as tool errors.
- CLI hard gate: single-line show/display only; exec job IDs, path
  containment, owner and ne:exec checks.
- Cisco IOSv collection: stable prompt/echo handling over CR.
- Remove legacy netx_api/mcp and mcp_server.py; add mcp.all.json;
  sync skills and docs.

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

tests/fixtures/zte_vpnv6/show-bgp-vpnv6

@@ -0,0 +1,13 @@
+MDN-BCP-CN1-ZM8SP#show bgp vpnv6 unicast summary | one-line 
+08:04:10 Indonesia Sat Sep 19 2026
+BGP router ID  : 124.195.96.248
+Local AS       : 4761
+All peers      : 2
+  Established  : 2
+All prefixes   : 0
+Neighbor        Ver As          MsgRcvd    MsgSend    Up/Down      State/PfxRcd
+FC00:A000:0:61:114::75
+                4   4761        14476867   2679817    5w4d         0
+FC00:A000:0:61:114::76
+                4   4761        14609910   2680356    5w4d         0
+MDN-BCP-CN1-ZM8SP#