doc: Align onboarding_basic tests with workflow + contract (acceptance criteria)

[Whiteks1]

Context

Tests must verify the contract/workflow alignment and prevent regressions. They should cover normal flow and key edge cases.

Affected paths

• docs/ai/tests/onboarding_basic.md

Steps

1. Ensure the test file lists the canonical states:
   start, ask_name, ask_goal, summary, end
2. Ensure the “Happy path” explicitly validates:
   • correct question at ask_name
   • correct question at ask_goal
   • summary is short + includes 2–3 actionable steps
   • summary/end do not ask additional questions
3. Add edge-case tests:
   • empty name / nonsense input
   • empty goal / very vague goal
   • repeated START while mid-flow (resume behavior if defined)
4. For each test, reference:
   • contract section (state/action table)
   • workflow state name
5. Remove duplicates/outdated scenarios.

Definition of Done

• Each canonical state is covered by at least one test
• Acceptance criteria are explicit and verifiable (pass/fail)
• Summary/end “no extra questions” is tested
• Tests match the contract and workflow wording/intent (no mismatched state names)