Remove legacy ND ≤3.2 modules for 2.0.0 (unified ND) (NDA-33)

[mtarking]

Summary

cisco.nd 2.0.0 targets the unified Nexus Dashboard (4.2+) OpenAPI. The modules that only work against ND 3.2 and earlier no longer function on the new controller, so this PR removes them and tombstones them for 2.0.0.

Because there is no intermediate 1.x release to deprecate in, this is a single-release removal: entries go straight to tombstone: in meta/runtime.yml (referencing a removed module now fails with an actionable message pointing at the ND-version limitation). To manage ND ≤3.2, users pin cisco.nd to a 1.x release and isolate the two generations in separate venvs / Execution Environments (only one version of a collection can be installed per collection path).

What changed

• Removed 25 modules (files + their tests/integration/targets/):
  • Insights / assurance / compliance: nd_compliance_analysis, nd_compliance_requirement_communication, nd_compliance_requirement_config_import, nd_compliance_requirement_config_manual, nd_compliance_requirement_config_snapshot, nd_compliance_requirement_config_template, nd_delta_analysis, nd_flow_rules, nd_interface_flow_rules, nd_instant_assurance_analysis, nd_pcv, nd_pcv_compliance, nd_pcv_delta_analysis, nd_policy_cam_statistics_hit_counts, nd_snapshot
  • Platform / cluster (ND ≤3.2 APIs): nd_api_key, nd_backup, nd_backup_restore, nd_cluster_config_route, nd_federation_member, nd_service, nd_service_instance, nd_setup, nd_site, nd_version
• nd_epoch routing converted from redirect: nd_snapshot → tombstone (its redirect target was removed).
• Removed orphaned shared code used only by the deleted Insights modules: plugins/module_utils/ndi.py, plugins/module_utils/ndi_argument_specs.py, plugins/doc_fragments/ndi_compliance_base.py (verified no surviving module imports them).
• meta/runtime.yml: added 26 tombstone entries and rebuilt action_groups.all with the 31 surviving unified modules (previously it listed only the legacy set + nd_rest).
• galaxy.yml: 1.5.0 → 2.0.0 (required: tombstones need the collection version ≥ removal_version).
• Changelog fragment: breaking_changes + removed_features.
• Docs: replaced the removed-nd_version examples in README.md and plugins/modules/nd_log.py with nd_rest equivalents.

Modules retained (31)

All nd_manage_*, nd_interface_* (non-flow), nd_fabric_update_group, nd_local_user, nd_log, nd_maintenance_mode, and nd_rest.

Reviewer notes / open questions

• The platform bucket (nd_api_key, nd_backup, nd_backup_restore, nd_federation_member, nd_service*, nd_setup, nd_site) is removed here rather than reworked onto unified APIs. If any of these should instead be re-implemented against ND 4.2+ endpoints, flag it and I'll pull it out of the removal set.
• Draft pending CI (ansible-test sanity / changelog lint) and confirmation of the base branch.

Verification done locally

• YAML validated for meta/runtime.yml, galaxy.yml, and the changelog fragment.
• Grep confirmed no surviving plugins/, README.md, or meta/ references to removed modules (only an unrelated internal nd_version parameter mention in the multisite orchestrator docstrings).
• Confirmed no unit tests or sanity ignore-*.txt entries referenced the removed modules.