test: add reason strings to the bare #[ignore] attributes

Start with the 20 locations listed in the issue, especially the bare attributes in the named files under tests/ and src/. Read each adjacent MODEL_DIR, skip message, or trailing comment, then run cargo test -- --list or compile the project. Done means every bare #[ignore] under src/ and tests/ has an appropriate reason string.

Summary

Twenty #[ignore] attributes carry no reason string in the attribute itself, against 335 in the repo that do (#[ignore = "..."]). In every case the reason text is already adjacent in the file: a MODEL_DIR const, an eprintln! skip message, or a trailing comment.

Background

A bare #[ignore] gives no hint in cargo test -- --list about why a test is skipped, so a reader cannot tell a hardware gate from a known-broken test. The convention across the repo is the = "..." form. This is mechanical: copy the adjacent reason into the attribute.

Proposed Solution

Fill each bare #[ignore] with the reason already sitting next to it. No hardware needed; compilation (or cargo test -- --list) verifies.

Implementation Notes

Verified bare sites in the current tree (20 total):

• tests/deepseek_v4_real_model.rs:55,111,145,236,362
• tests/qwen38_mtp_chain_parity.rs:127,202,447,523,612,678
• tests/ernie4_5_moe_vl_parity.rs:132
• tests/qwen3_omni_moe_parity.rs:66
• src/models/diffusion_gemma/tests.rs:448,803
• src/downloader/tests.rs:547
• src/tokenizer/tiktoken.rs:368,383,394,405 (these carry a // Requires model files trailing comment but no reason in the attribute)

Note: the two src/models/diffusion_gemma/tests.rs sites were missed by the original enumeration; they are included above.

Convention examples: tests/turbo_kv_e2e.rs:598, :633, :657. Adjacent reason sources: tests/deepseek_v4_real_model.rs:52 (MODEL_DIR) and its skip message; src/tokenizer/tiktoken.rs:368 (// Requires model files); src/downloader/tests.rs skip block.

Acceptance Criteria

• Zero bare #[ignore] remains under src/ and tests/.

---

Original Suggestion

Title: test: add reason strings to the twenty bare #[ignore] attributes

Twenty #[ignore] attributes carry no reason string, against 330 in the repo that do (#[ignore = "..."]). In every bare case the reason text is already sitting adjacent in the file — a MODEL_DIR const, an eprintln! skip message, or a trailing comment.

Evidence

Bare sites: tests/deepseek_v4_real_model.rs:55,111,145,236,362; tests/qwen38_mtp_chain_parity.rs:127,202,447,523,612,678; tests/ernie4_5_moe_vl_parity.rs:132; tests/qwen3_omni_moe_parity.rs:66; src/tokenizer/tiktoken.rs:368,383,394,405; src/downloader/tests.rs:547.

Convention examples: tests/turbo_kv_e2e.rs:598, :633, :657. Adjacent reason sources: tests/deepseek_v4_real_model.rs:52 (MODEL_DIR) and :59-61 (skip message); src/tokenizer/tiktoken.rs:368 (// Requires model files); src/downloader/tests.rs:544-545.

Suggested fix

Copy each adjacent reason into the attribute. No hardware needed; cargo test -- --list (or just compilation) verifies.

Acceptance criteria

• Zero bare #[ignore] remains under src/ and tests/