docs: add CLA policy pilot

[sidmohan0]

What changed

• add a Harmony-derived DataFog Individual CLA using Outbound License Option Five
• document contributor scope, exemptions, employer-owned work, records, and historical contributions
• add an administrator runbook for the SAP CLA Assistant pilot and organization rollout
• update contribution and pull request guidance

Why

DataFog needs an authenticated, enforceable CLA workflow for external contributors while preserving contributor ownership and retaining commercial and future relicensing flexibility.

Impact

This PR prepares the policy and rollout. It does not install or activate CLA Assistant. Counsel approval, a public agreement Gist, a test pull request, and the required license/cla branch check remain rollout prerequisites.

Validation

• git diff --check
• pre-commit run on all changed files
• verified CLA Assistant status context is license/cla
• compared the draft against the official Harmony HA-CLA-I and Apache ICLA source agreements