Simplify tracker to Vault only

[awei-cefai]

Summary

• Makes the tracker action Vault-only.
• Removes sender routing, central sender, and legacy compact payload paths.
• Always reads the raw GitHub event from GITHUB_EVENT_PATH for PR, review, and push events.
• Adds only top-level CEF fields: event_type, github_event_name, delivery_id, optional tokens, and wiki_check_branches.
• Delegates to cef-ai/Cef-Send-Event-Action@awei/central-sender-mode with only event_type and event_payload.

Minimum caller setup

• CEF_VAULT_WALLET_KEYSTORE_B64 secret
• CEF_VAULT_WALLET_KEYSTORE_PASSWORD secret
• Optional but recommended: CEF_AGENT_ID variable
• GITHUB_TOKEN: ${{ github.token }} in job env, or pass github_token

Validation

• ruby -e 'require "yaml"; YAML.load_file("action.yml")'
• bash -n on the payload shell step after substituting github.event_name=push
• Local payload step smoke against a push-shaped event produced raw GitHub JSON plus CEF metadata.
• git diff --check
• Fresh GitHub workflow run 26218604344 downloaded this tracker action at SHA 6864085d18367f8db93cf5d56e55756ce6ef81b7 and the delegated send action at SHA 58d533bee42de19e25f53d0c6f2fe1e4c3c91843.
• The run published successfully with zero unexpected-input or Polkadot duplicate-version warning lines.
• Verified workflow delivery 26218604344-1 in productivity_store as repo CEF-AI/Productivity-Engineering-Intelligence, action branch_push, entry Pushed to awei/test-vault-sender-20260517124220: Retest simplified Vault tracker.

Release note

This branch still points at the send action feature branch for testing. Before release, point it at the merged send action ref or a version tag.