Present ModelForge as a product and platform

[michaelbawuah]

Changes

• Use product and engineering language in the README, deployment validation documentation, CI labels, and demo defaults.
• Replace the presentation brief with a platform overview covering architecture, lifecycle, reliability, access, and deployment status.
• State clearly that the AWS reference deployment has not been launched publicly.

Verification

• GitHub CI run #180 passed: Python tests and lint, Go tests and vet, Terraform validation, container builds, and live Compose smoke.
• Python files compiled, YAML workflows parsed, and git diff --check passed locally.
• Audience-specific wording was removed from the current repository files.

Earlier commit titles remain in Git history; no history rewrite was performed.