docs: make AI portfolio workflow reproducible

[Masterleeaus]

Summary

• add docs/AI_ENGINEERING.md with a source-backed map of local intelligence, optional cloud AI, agent-oriented building blocks, authority controls and limitations
• make the TypeScript offline companion reproducible with a declared Node engine, pinned lockfile and CI npm ci
• update the README quickstart and link the implementation map
• ignore local dependency/test output
• remove the obsolete import workflow that only targeted the already-merged feature/full-engine-template-upgrade branch and an external source archive

Evidence

• base inspected at 79c3424be37214ea11b9bb73a3b55f44d1b8f0b0
• local audit: 336 PHP files, 70 JSON files, all JSON parsed successfully
• npm ci --ignore-scripts --no-audit --no-fund
• npm test: TypeScript build plus 4/4 offline tests passed
• no AGENTS.md or .agents/ instructions exist in the repository
• no open PRs; historical PR Publish Interaction Engine commerce and multi-vertical template catalogue #4 is merged and its host-verification caveat is preserved

Scope

Documentation and build reproducibility only. No source, tests, migrations, distribution files, provenance records, credentials or branches were deleted or rewritten.