[typotter]

Motivation

A reached prerequisite flag that produces no assignment is an invalid dependency-graph state. The root evaluation must fail closed instead of treating the missing assignment as a normal condition miss and continuing its allocation waterfall.

Changes

• Add an allocation-free dependent-no-assignment-parent and a dependent-no-assignment-root whose first allocation depends on the parent's assigned variant.
• Add a later unconditional, logged fallback with a distinctive must-not-return value. This proves a misconfigured prerequisite cannot allow the protected root waterfall to continue: the temporary no-match evaluator returns this canary value, while the fail-closed evaluator returns the caller default.
• Add exact GENERAL evaluation-event expectations for the parent and root, require no exposures, and reject unmatched telemetry.
• Validate with python3 ci/validate-fixtures.py, the validator unit tests, focused dependent-suite consistency assertions, git diff --check, and both evaluator behaviors.

Decisions

The fixture intentionally has no NOT_ONE_OF allocation because evaluation fails before the dependency operator can logically run. The change is limited to the dependent-flags UFC and case data; it does not alter schemas, validators, evaluator code, system tests, or documentation.

Checklist

• JSON files are valid (no syntax errors)
• New test cases reference existing flags in config/ufc-config.json
• New flags have corresponding test cases in evaluation-cases/
• Expected results match the flag configuration logic