Pair End with For loops and simulate For Global/Player Variable #50

Problem

After athena#46 (PR #49), Bastion (/Users/teakowa/Repos/wrightkit/.task-scratch/bastion/bastion.ow, scenario .../bastion/scen.json; run per .task-scratch/bastion-loop-state.md) stops with not_modeled: "End without an opening action", tick null, in rule initialize hero list. block_maps in blocks.rs does not track For/For Global Variable/For Player Variable openers, so the End of a For loop is unpaired.

Scope

• Make the block map pair End with all Workshop block openers used by Bastion (For Global Variable, For Player Variable, While, Loop If-free forms, If/Else If/Else).
• Model For Global/Player Variable execution (range start, stop, step; the loop variable written each iteration) only as far as the Workshop semantics in workshop-rs define it. A behavior without a passing capture fixture is recorded in docs/findings.md as modeled-not-measured, per AGENTS.md.

Acceptance criteria

• Tests: a rule with a For Global Variable loop containing an If runs to the expected variable values; a For inside If pairs its End correctly; an End without an opener still stops not_modeled.
• The Bastion run moves past this stop; record the next stop in the PR body.
• Standard gates (fmt, clippy -D warnings, tests, wasm32 build) and docs updates in the same PR.