scripts, examples: stop forcing the deprecated Miles router in launchers

[Shi-Dong]

Summary

The Miles router is deprecated in favour of sgl-router, but 14 launcher recipes still passed --use-miles-router unconditionally, so every run started from them took the deprecated text-based routing path.

There was no way to opt out from the caller side:

• --use-miles-router is declared action="store_true" with no negated form, so it cannot be switched off by appending anything to --extra-args / the trailing arg list.
• None of the Python launchers expose a ScriptArgs field for it.

Editing the recipe was the only workaround. This PR drops the flag everywhere it was hard-coded, so router_manager falls through to the sgl-router branch.

scripts/ (2 files) — run_glm5_1_744b_a40b_lora.py, run_glm5_2_744b_a40b_lora.py.

examples/ (13 files) — the LoRA recipes (dev.sh, run-kimi-k25-megatron-lora.sh, run-qwen2.5-0.5B-megatron-lora.sh, run-qwen2.5-3B-megatron-lora-disaggregated.sh, run-qwen2.5-3B-megatron-lora-disaggregated-multi-node.sh, run-qwen3-4b-megatron-lora-result.sh), the multi-LoRA driver (run_multi_lora.py), the four low-precision recipes, and the reproducibility recipe. The p2p profiling recipe also had a dead commented-out occurrence, removed so the flag does not read as an option worth re-enabling.

Deliberately out of scope

• The argument itself. miles/utils/arguments.py and all router plumbing (router_manager.py, sglang_engine.py, dashboard/, router/) are untouched. Retiring the flag is a separate decision from unpinning the recipes.
• Tests. tests/e2e/sglang/test_r3_router_equivalence.py exists specifically to compare Miles router against sgl-router, and the router/dashboard unit tests exercise the same code — removing the flag there would delete the coverage rather than modernise it. Three e2e tests pass it incidentally (tests/e2e/lora/test_lora_qwen2.5_0.5B.py, tests/e2e/megatron/test_quick_start_glm4_9B.py, tests/e2e/megatron/test_glm5_2_744b_a40b_5layer_nvfp4.py); happy to clean those up here if reviewers prefer tests in scope.
• Docs. The /advanced/miles-router page documents R3 rollout routing replay, not this flag.

Test plan

• grep -rn -- "use-miles-router" scripts/ examples/ returns no matches.
• bash -n passes on all 12 edited shell recipes; the two edited Python launchers and the multi-LoRA driver still compile.
• End-to-end GRPO LoRA run of the GLM-5.2 gsm8k example on 4x H200, before and after the change:
  python scripts/run_glm5_2_744b_a40b_lora.py train --model-name GLM-5.2_5layer --task gsm8k --num-gpus-per-node 4 --num-rollout 5
  Both complete all 5 rollouts and save adapters. After the change the Megatron arg dump reports use_miles_router ... False and router_manager logs Router launched at <host>:<port> from the sgl-router branch. Train/rollout logprob parity is unchanged (max abs diff 2.2e-4 against a mean logprob of -10.2).
• The other 13 recipes are the same single-line deletion and were not individually run.

[gemini-code-assist]

Caution

The consumer version of Gemini Code Assist on GitHub has been sunset. All code review activity has officially ceased.