[BillLeoutsakosvl346]

Summary

• resolve selector context from condition-visible trigger fields while a block is in trigger mode
• pass trigger mode through canvas options, label hydration, comparison labels, and top-level fork reconfiguration
• preserve action-mode and nested-tool behavior
• keep coverage to three central selector-context regressions

Testing

• bun run --cwd apps/sim test -- lib/workflows/subblocks/context.test.ts
• scoped biome check for all six changed files
• bun run --cwd apps/sim type-check
• git diff --check

Prerequisite for #6934.