v0.1.6

Fix recursive aliases, callbacks, equality, and switch flow

SUB-817: Bound recursive alias comparisons and recognize equivalent nested
instantiations without overflowing the compiler stack.

SUB-772: Accept value-returning functions in void callback positions while
preserving explicit return annotations and result dropping.

SUB-949: Check equality overlap symmetrically so nullable values work on
either side, preserving enum and literal comparison checks.

SUB-913: Simplify overlapping logical result types so inferred strings
support template interpolation without changing short-circuit behavior.

SUB-852: Share completion analysis across switch fallthrough and return
checks, accounting for try, catch, finally, and nested switch transfers.

Add 21 regression fixtures covering accepted programs and invalid cases.

Integrate upstream literal inference by sharing compound arithmetic rules,
preserving literal-field diagnostics, simplifying ternary and nullish result
types, and updating affected fixtures and lint formatting.

Co-Authored-By: OpenAI Codex <noreply@openai.com>