[codex] Add FDO registration pack docs

[joy7758]

What changed

This PR adds the FDO-facing registration and outreach pack for the current operation-evidence profile line.

It includes:

• the FDO registration pack note
• an FDO Testbed registration draft
• a Peter / Sven outreach draft
• an LDT4SSC / DS4SSCC module pitch skeleton
• README and status updates that explain the relationship between the canonical profile, FDO_OPERATION_EVIDENCE_PROFILE_V0_1, and ARO_AUDIT_PROFILE_V1

Why it changed

The repository already had the minimal profile, schema, examples, validator, and demo.
This PR closes the remaining packaging gap by making the current implementation line easier to register, present externally, and reuse in FDO / data-space conversations without creating a second implementation surface.

External result

The FDO Testbed object has been registered as:

• FDO_OPERATION_EVIDENCE_PROFILE_V0_1
• 21.T11966/fdo-operation-evidence-profile-v0-1
• https://typeregistry.testbed.pid.gwdg.de/#objects/21.T11966/fdo-operation-evidence-profile-v0-1

Validation

• git diff --check
• ./.venv/bin/agent-evidence validate-profile examples/minimal-valid-evidence.json
• ./.venv/bin/agent-evidence validate-profile examples/invalid-missing-required.json

Notes

This PR intentionally stages only the FDO-facing documentation pack.
Other unrelated local changes in the worktree are left untouched.