Model element-context array values (Sorted/Filtered Array, Is True For All/Any, Current Array Element/Index) #60

Problem

Follow-up to athena#56. The first PR modeled the element-free general and array values; these remain because they evaluate their operand once per element with 'Current Array Element' (and 'Current Array Index') bound.

Scope

'Current Array Element', 'Current Array Index', 'Sorted Array', 'Filtered Array', 'Is True For All', 'Is True For Any', 'Mapped Array' if Bastion's run reaches it, plus 'Evaluate Once' and 'Local Player' if they prove to be the blocker ahead. Semantics follow 'workshop-rs' definitions; array and null coercions follow 'docs/architecture.md'.

Acceptance criteria

• One unit test per value family with a boundary case (empty array, null operand, out-of-range index).
• Standard gates: fmt, clippy -D warnings, tests, wasm32 build; update 'docs/simulator-interface.md' in the same PR. A construct without a passing capture fixture is recorded in 'docs/findings.md' as modeled-not-measured.
• The Bastion run moves past 'value evaluateOnce' at tick 0 (the stop athena#56's first PR left); record the next stop in the PR body.