fix(native): preserve callable declaration identity

[samchon]

Closes #2238.

This draft reserves the remaining function-shaped declaration identity defect. Call-only and construct-only interfaces and type literals must keep the same function metadata behavior as mutually assignable aliases, while required members and index signatures remain structural boundaries.

The campaign lead split this issue from #2200 under the five-row admission table. Runtime-native File and Blob provenance has a different root cause, focused oracle, rollback unit, and acceptance matrix; it remains in re-scoped draft #2257. This claim owns only the callable declaration-shape invariant and its downstream #2252 integration dependency.

This is an implementation-free reservation at 9cc3ade21ae516e624929650adb7424ce470c1e9 from master 3f59f641a92e6a730072a65fda2ed7f2ec90c9ad. Product implementation, local verification, solo self-review, independent verification, and prospective and exact-merged integration gates are pending. The exact-SHA campaign Actions record is maintained separately and is not acceptance evidence.

Campaign constraints: no package version, tag, release, publication, or unrelated schema-interface change.

[samchon]

Superseded by #2266.

The maintainer stopped all local building and testing after the machine ran out of resource headroom, and directed that the residual campaign pull requests be consolidated into one with verification delegated to GitHub Actions CI. This unit's net diff is carried into #2266 as its own squashed commit, so its issue keeps a separate acceptance boundary, rollback unit, and failure attribution inside the shared pull request.

Closing this one. The branch is left in place; nothing is deleted.