Add Routed and AI Routed fabric types

[mtarking]

Related Issue(s)

Closes #314

Proposed Changes

Adds two new ND fabric modules for Routed fabrics, built on the pydantic model +
state-machine architecture:

• nd_manage_fabric_routed — standalone Routed fabric management (fabric type routed)
• nd_manage_fabric_ai_routed — AI/ML Routed fabric management (fabric type aimlRouted),
  subclassed from the routed base with AI QoS always enabled (frozen aiml_qos)

Per the OpenAPI spec (docs/openapi/4.2.1/manage.json), routed/aimlRouted share
byte-for-byte identical property schemas with vxlanEbgp/aimlVxlanEbgp — only the
type discriminator differs — so the routed models mirror the eBGP VXLAN implementation.

New/changed files:

• plugins/module_utils/models/manage_fabric/manage_fabric_routed.py — RoutedManagementModel, FabricRoutedModel
• plugins/module_utils/models/manage_fabric/manage_fabric_ai_routed.py — AimlRoutedManagementModel, FabricAiRoutedModel
• plugins/module_utils/orchestrators/manage_fabric_routed.py — ManageRoutedFabricOrchestrator
• plugins/module_utils/orchestrators/manage_fabric_ai_routed.py — ManageAiRoutedFabricOrchestrator
• plugins/modules/nd_manage_fabric_routed.py, plugins/modules/nd_manage_fabric_ai_routed.py
• plugins/module_utils/models/manage_fabric/enums.py — added FabricTypeEnum.ROUTED / AIML_ROUTED
• plugins/module_utils/models/manage_fabric/constants.py — wired ROUTED into pool/pattern/string maps
• tests/unit/module_utils/models/test_manage_fabric_routed.py
• tests/integration/targets/nd_manage_fabric/tasks/fabric_routed.yaml, fabric_ai_routed.yaml (+ main.yaml/vars/main.yaml wiring)
• changelogs/fragments/add_nd_manage_fabric_routed.yml

Test Notes

• Unit tests: python -m pytest tests/unit/module_utils/models/test_manage_fabric_routed.py
  → 4 passed. Covers routed model type/identity, AI routed aiml_qos=True, aiml_qos
  exclusion from argspec, and the locked/frozen aiml_qos field rejecting False.
• Integration tests added under tests/integration/targets/nd_manage_fabric/ covering
  merged (create/idempotent/update), replaced (create/idempotent), overridden, and
  deleted (delete/idempotent), plus live API validation of management.type
  (routed / aimlRouted) and aimlQos == true for the AI variant.
• YAML validated for all new/modified integration files.

Cisco Nexus Dashboard Version

4.2.1

Related ND API Resource Category

• analyze
• infa
• manage
• onemanage
• other

Checklist

• Latest commit is rebased from develop with merge conflicts resolved
• New or updates to documentation has been made accordingly
• Assigned the proper reviewers