fix: handle non-double types when converting to i1 for object boolean fields

[cs01]

Summary

• Object literal boolean fields (e.g., { active: true }) could produce invalid LLVM IR when the boolean value was i64 or i1 type instead of double
• Two fcmp one double instructions in object.ts now properly check the value type first: i1 passes through directly, i64 uses icmp ne, and only double uses fcmp
• Same class of bug as fix: handle boolean values correctly in template literal interpolation #240 (template literal booleans) — generateBoolean() returns i64, not double

Test plan

• New fixture objects/object-boolean-field.ts tests boolean fields in object literals
• npm run verify:quick passes (all tests + Stage 1 self-hosting)

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