Refresh media comment action payload

[subzeroid]

Summary

• mirror the current media_comment() write payload from instagrapi, including feed action context fields
• fix pooled live account URL construction so an existing count query param is overridden instead of duplicated
• add regression coverage for async comment payload and live account URL construction
• add a manual comment live workflow target and update the live comment test to upload/read back/cleanup its own media fixture
• document that comment creation remains a write action subject to Instagram spam/trust checks

Mirrors subzeroid/instagrapi#2538.

Tests

• .venv/bin/python -m pytest tests/regression/test_comments.py::CommentRepliesRegressionTestCase::test_media_comment_posts_current_action_context tests/regression/test_live_smoke.py::LiveSmokeRegressionTestCase::test_fetch_accounts_overrides_existing_default_count -q
• .venv/bin/python -m pytest tests/regression/test_comments.py tests/regression/test_live_smoke.py -q
• .venv/bin/python -m ruff check aiograpi tests
• .venv/bin/python -m ruff format --check aiograpi tests
• .venv/bin/python -m pytest -sv tests/legacy.py::ExtractorsRegressionTestCase tests/legacy.py::ImageUtilSafeRemoteFetchTestCase tests/legacy.py::DirectExtractorRegressionTestCase tests/legacy.py::PublicRegressionTestCase tests/legacy.py::PolarisProfileNormalizationTestCase tests/legacy.py::CaptchaHandlerMixinRegressionTestCase tests/legacy.py::NoteMixinRegressionTestCase tests/legacy.py::LocationMixinRegressionTestCase tests/legacy.py::ChallengeRegressionTestCase tests/legacy.py::AuthAndStoryRegressionTestCase tests/legacy.py::ClientTestCase tests/legacy.py::DownloadRegressionTestCase tests/legacy.py::DirectMixinRegressionTestCase tests/legacy.py::UserMixinRegressionTestCase tests/legacy.py::TimelineRegressionTestCase tests/legacy.py::StoryConfigureRegressionTestCase tests/legacy.py::UploadRegressionTestCase tests/legacy.py::SignUpTestCase tests/legacy.py::NotificationMixinRegressionTestCase tests/legacy.py::ChapiPortedRegressionTestCase tests/regression
• .venv/bin/python -m mkdocs build --strict
• ./scripts/check-mypy-baseline.sh
• .venv/bin/python -m build

Live verification

• Local tests/legacy.py::ClientCommentExtendTestCase::test_media_comment did not reach the comment endpoint because account setup failed on proxy 302 Found during launcher/sync/.
• Manual GitHub workflow target now handles missing TEST_ACCOUNTS_URL as an explicit skip instead of falling back to dummy credentials: https://github.com/subzeroid/aiograpi/actions/runs/26125558847
• Real comment-write live verification passed in the upstream sync PR for instagrapi: https://github.com/subzeroid/instagrapi/actions/runs/26124367512