Finalize managed values on exception unwind

• Type: feature
• Status: done
• Owner: Codex
• Unblocks: feature-managed-string-default
• Opened: 2026-06-06 (from todo.md §2d/§4 + rainy-afternoon)

Motivation

Managed locals (refcounted AnsiString, dynamic arrays) are finalized on normal scope exit, but not on the exception unwind path. Leaks/incorrect refcounts when an exception crosses a scope holding managed values. Blocks making managed strings the default.

Scope

• Emit unwind-path finalization for managed locals and dynamic arrays when an exception leaves their scope (mirror the normal scope-exit cleanup).
• Cover record/class fields holding managed values.

Acceptance

A test that raises through a scope owning managed strings/arrays shows correct release (no leak, no double-free); self-host fixedpoint holds.

Log

• 2026-06-12 — Done in commit f2889d0. Regression: test/test_managed_exception_cleanup.pas; verified with make bootstrap, make test, make test-nilpy, and make fpc-check.
• 2026-06-12 — Claimed by Codex; starting unwind-path managed cleanup work.
• 2026-06-06 — ticket opened from todo.md §2d/§4.