docs: add project discovery and delivery lifecycle

[MartinKalema]

What changed

• add the discovery workflow for ambiguous client requests
• add the complete engineering project lifecycle from intake through production learning
• connect discovery, requirements, planning, execution, assurance, and human constraints

Why

Engineers need one explicit path for turning an ambiguous request into an understood, estimated, controlled, and accepted outcome. These documents consolidate the existing engineering-system guidance into that operating sequence.

Impact

The documentation now provides a repeatable entry point for ambiguous projects and a step-by-step lifecycle that can be used for training, simulations, project governance, and delivery qualification.

Validation

• reviewed the branch diff against current main
• confirmed that the PR contains only two Markdown files
• ran git diff --check