chore: add LICENSE, IDEAS.md, AGENTS.md, PENDINGS.md, CI, and test infrastructure

[teckedd-code2save]

Summary

IntentEngine is a 1-star research repo ("anchors intent and intervenes when behavior deviates" — the concept behind IntentEngine-mvp). It has a README and a description, but zero project infrastructure: no LICENSE, IDEAS.md, AGENTS.md, PENDINGS.md, CI, or tests — and no open issues tracking any of it.

What to do

1. LICENSE — add an MIT license file at repo root.
2. IDEAS.md — capture the research direction: behavioral-science interventions, context-aware interruption, and the IntentEngine-mvp pipeline as forward-looking ideas.
3. AGENTS.md — document repo purpose, layout, and conventions so agents can work in it.
4. PENDINGS.md — record known sharp edges/limitations of the current research state.
5. CI workflow — add .github/workflows/ci.yml (lint + typecheck/build if a package.json exists; otherwise a smoke check) with workflow_dispatch enabled.
6. Tests — add a minimal test setup appropriate to the language used.

Why this matters

• No LICENSE blocks contribution and downstream use.
• This repo is the concept parent of IntentEngine-mvp (which already has the full doc set); matching it makes the pair navigable.
• Zero CI/tests means nothing verifies the research code still runs.

Acceptance criteria

• LICENSE (MIT) at repo root
• IDEAS.md with 5+ research/feature ideas
• AGENTS.md describing repo purpose and layout
• PENDINGS.md with known limitations
• CI workflow that runs on push (with workflow_dispatch)
• At least one test file