fix: add missing setvariabletype in array filter, map, reduce, some, every, includes, shift

[cs01]

Summary

• Add missing setVariableType calls for return values in 10 array method codegen functions
• Numeric filter and map were missing type tracking (%Array*), while their string counterparts had it
• some, every, includes (both numeric and string variants) returned double from raw sitofp without type tracking
• Numeric shift returned double from raw phi without type tracking
• String reduce used raw emit for load instead of emitLoad (which auto-tracks type)

These gaps mean downstream code can't determine the return type of these array operations, which can cause wrong IR when the result is used in assignments, parameter passing, or chained operations.

Test plan

• All 448 tests pass (node + native)
• Self-hosting chain passes (--quick)

🤖 Generated with Claude Code