chore: remove SAM2_DUMP_DIR dumps and dbg_ tensor markers

[PABannier]

What

Removes debug-session leftovers from production code paths in sam3.cpp:

• SAM2_DUMP_DIR dumps in the Hiera PE precompute (bkg_interp / win_tiled) and in sam3_segment_pvs (sparse embeddings, image feats, decoder outputs and intermediates).
• dbg_* tensor names and their ggml_set_output markers: Hiera patch embed / after-PE / blocks 0,1,2,5,21 / FPN laterals, the two-way block internals, and the decoder's dbg_dec_{queries,keys}_out.
• The block-0 dump flag in sam2_hiera_block_forward and the block_idx parameter it used (nothing else read it).
• The static _sa_call_count / _sa_merge_count counters in sam3_sam_attention. Besides being debug-only, they were hidden global state.
• ggml_set_output on sam_dec_tokens_initial and sam_dec_block%d_{queries,keys}. Those names are kept because the test API still looks them up with ggml_get_tensor and sets its own outputs.

Why

These blocks only existed to compare against Python during debugging. The extra ggml_set_output markers also stopped the graph allocator from reusing those intermediate buffers.

Verification

Parity tool, byte-compared against deterministic origin/main baselines. It covers encode_image, segment_pvs with point and box prompts, and the visual tracker's add_instance + propagate_frame.

PARITY OK   edgetam_f16 gpu0
PARITY OK   edgetam_f16 gpu1
PARITY OK   sam2.1_hiera_tiny_q8_0 gpu0
PARITY OK   sam2.1_hiera_tiny_q8_0 gpu1

Full Release build: no errors. The only warnings come from ggml and stb, and they are already on main.

 1 file changed, 2 insertions(+), 155 deletions(-)

Caveats

• No full SAM3 model was available locally, so the text/PCS path is only verified to compile. None of the removed code is on that path.
• Out of scope on purpose (sibling PRs handle these): the test/debug API regions, including their own SAM2_DUMP_DIR blocks and lists of dbg_* names; the EdgeTAM profiler; and the #if 0 manual SDPA block. The Hiera dump in the test API skips missing tensors, so it still runs; it just finds nothing to dump.

🤖 Generated with Claude Code

https://claude.ai/code/session_01M2qLmQ9ag49hT61V6i9qAq