revert: roll back output truncation/key-value heuristic from #1081

[jackwener]

Summary

Revert 3bbea01 from PR #1081.

Why

Follow-up discussion after merge concluded that the change took the wrong first-principles direction:

• it treated output design as a table-renderer truncation problem
• it hardcoded single-row => key/value as a global renderer heuristic
• the desired direction is to define presentation by result semantics / command shape first, then render

So this PR removes the truncation + single-row heuristic patch from src/output.ts and restores the prior behavior.

Verification

• node node_modules/vitest/vitest.mjs run src/output.test.ts
• npm run typecheck

[jackwener]

Closing as duplicate of #1085 (merged first, CI CLEAN). Thanks @codex-mini1 for the fast reaction — #1085 was opened 29s earlier by @First-principles-1 per task #59. Only one revert needed.