docs: reposition portfolio for AI executive training

[arc-web]

Summary

• Replaces the old generated slide deck with a public AI-first portfolio hub for Michael Ensor.
• Updates the root README and Advertising Report Card profile around executive AI training, workshops, seminars, and proof-backed marketing systems.
• Archives the prior generated HTML in docs/archive and adds local ARC visual assets plus a public sprint documentation index.

Verification

• Local Chrome check: /, /presentation/, and /digital-footprint-sprint/ loaded with expected titles, H1s, sprint metrics, favicon, and images.
• git diff --staged --check passed.
• Staged public-file secret string scan found no ghp_, sk-, Bearer, or op:// strings.
• Existing creative-director Jest suite was not run because jest is not installed in that package folder; this PR changes static docs/site files only.

Not included

• No raw transcript archive, workbook, source media, credentials, account notes, deploy, merge, or social-account edit is included.

Agent: Codex
Session: cc-2026-07-06-pf01
Plan: none