Address PR #240 review feedback from @calesthio:
1. dashscope_image: save EVERY returned image URL, not just the first.
The tool advertised multiple_outputs and accepted n>1 but only read
content[0], silently dropping paid outputs. Now collects all image
URLs across choices/content and downloads each to a distinct indexed
path (foo.png -> foo_1.png, foo_2.png, ...). images_generated now
reflects the actual count downloaded.
Per Qwen Cloud docs, a multi-output task is SUCCEEDED if at least one
image is generated; choices with finish_reason != "stop" are skipped
to avoid downloading partial/failed results.
2. Complete idempotency_key_fields so different requests no longer
collide and reuse stale artifacts:
- image: + negative_prompt, seed, prompt_extend, watermark
- tts: + instructions
- asr: + enable_words, language_hints
Adds 19 regression tests (114 total, all pass, no API keys needed):
- TestDashscopeImageMultiOutput: URL extraction across choices / within
one choice / failed-choice skipping, path resolution for
single/multi/no-extension, end-to-end multi-image download with a
mocked 3-URL DashScope response verifying all 3 files land on disk,
single-image legacy path behavior
- TestDashscopeIdempotencyKeys: field presence + key-differs-on-value
for every newly added field across all three tools
b4bed5735a