fix(relinker): preserve Linux executable exports and ELF section addresses

[tototomate123]

What

Split from #1616, following its review. Map section addresses through load segments; preserve defined executable exports, DT_HASH and DT_DEBUG so Linux symbol lookup and debugging can find them. Includes an executable-export regression and malformed-symbol-table check. Two commits.

Tested

Linux x86-64, GCC 16.2.1, Release. linux_executable_exports passes (generated Linux ELF loads and calls its exported symbol; malformed input is rejected). Relinker builds. Conventions and whitespace checks pass on current main (5edae353).

Depends on

None for build. HFW integration also needs #2786 (loader), #2787 (filesystem), #2788 (http), #2789 (apr), #2790 (shader). #1269 (media), #1339 (VRR), #1586 (unwind) and #1436 (imports) are now on main. Local image-table experiments are excluded; open #757 → #758 overlaps them, and #920 is closed without merging. Earlier combined integration reached menu/loading UI; these isolated branches have not been game-tested and gameplay is unverified.

Checklist

• Based on current main; no duplicate implementation found beyond superseded fix(linux): resolve loader and APR failures exposed by HFW #1616
• One topic per PR
• No code comments except technical debt
• Unimplemented paths throw; offline HTTP limitations documented
• No investigation notes, logs or images committed
• No new third-party dependencies
• Generic behavior; no title-specific dispatch
• Depends on: none for build; HFW integration requirements listed above
• AI-assisted: yes, Codex

[github-actions]

Thank you for your interest in the project! We are sorry, but we cannot accept more PRs while we work through the existing backlog. This PR has been automatically closed and labeled "intake paused". This is not a judgment of the quality of your changes.

[adriadam10]

Checked on Linux x86-64 (relinker scope, 95/95 ctest): linux_executable_exports passes with the change and fails without it (exit code 1 from the probe), and the malformed DT_OS_SYMTABSZ case is rejected. The DT_HASH chain and the section address mapping through PT_LOAD look right. Merging once CI is green.