fix(build): main is RED — hf_snapshot.h calls HfSnapshot before it is declared (#551, #546)

[localai-bot]

main does not build. Closes #551 and #546.

Nemotron35LightningSnapshot() landed with the Nemotron-3.5 goldens (#517) ten lines above the HfSnapshot definition it calls. Name lookup in the body of a non-template function only sees declarations that precede it, so the header does not compile:

tests/parity/hf_snapshot.h:52:10: error: 'HfSnapshot' was not declared in this scope
   52 |   return HfSnapshot("models--nvidia--NVIDIA-Nemotron-3.5-Lightning-30B-A3B-NVFP4",
      |          ^~~~~~~~~~

That header is included by 16 test translation units, including the SACRED 27B and 35B parity gates, so CPU builds fail outright — build-test-cpu is red on main at 8b00f79f2 and on every PR branched from it.

The fix puts the accessor where every other accessor in this file already sits: below HfSnapshot, next to the Qwen and DFlash ones. Nothing else moves and the pinned revision constant stays with its documentation.

Evidence

• RED before: g++ -std=c++20 -fsyntax-only on the header fails at the line above.
• GREEN after: compiles clean. That compile is the test, and the 16 TUs already run it in CI.
• The two checkers that PARSE this header for its pins stay green: test_check_snapshot_pins 19/19, test_online_gate_server_binary 20/20.
• scripts/agent-preflight.sh --staged: All gates green.

Worth recording: Nemotron35LightningSnapshot() has no caller yet — it is staged for the gate #517 owes, which is why nothing but the build noticed.

FOLLOWING_AGENTS_PROTOCOL

[localai-bot]

Superseded by #556 (fafa16f0f), which landed the same fix on main eleven minutes after this branch was cut. Closing rather than merging, because merging would be actively harmful:

git merge-tree --write-tree origin/main HEAD resolves with no conflict — #556 moved the block to just after HfSnapshot (line 68), this branch moved it to the end of the namespace (line 168), so git sees a delete-plus-insert on each side and takes both. The merged header defines Nemotron35LightningSnapshot() twice, at lines 75 and 188:

merged.h:188:20: error: redefinition of 'std::string parity::Nemotron35LightningSnapshot()'
merged.h:75:20: note: previously defined here

GitHub reports MERGEABLE, so nothing would have warned. This is the hazard AGENTS.md names directly: merging two such edits cleanly is worse than conflicting.

The defect itself is fixed on main and verified: g++ -std=c++20 -fsyntax-only is clean on origin/main's copy of the header. The review that caught this also mutation-tested the class — moving the block back above HfSnapshot fails to compile, a forward declaration makes it compile, and a declaration without a definition fails at link — so the build genuinely is the regression guard here and no extra checker is owed.

No objection to #556's placement; this branch's end-of-namespace variant is not worth a follow-up.