emrg: add workflow_dispatch to Test workflow — manual CI re-trigger without empty commits

[argszero]

Summary

During tonight's GitHub Actions Partial System Outage, push events stopped creating Test runs: 4 master merge pushes (d3fab7a, 386e114, 86e265f, 6093b45) and 3 feature-branch pushes produced no runs at all (verified via check-runs API), while pre-queued runs slowly drained (the last one green at 20:01Z). Master went ~2.5h without any CI verification — re-triggering required an empty commit (emrg: re-trigger CI (runner cancellation)), which is a git-history polluter and may itself be dropped if the push-event pipeline is down.

Change

Add workflow_dispatch: to .github/workflows/test.yml triggers. This enables gh workflow run test.yml --ref <branch> — an API-triggered path that bypasses the push-event pipeline entirely.

Evidence (tested live this cycle)

• While push events for master were still being dropped, gh workflow run test.yml --ref feature/ci-workflow-dispatch created run 31127419068 immediately (in_progress → success in ~90s, 15 steps).
• The green run also verifies the actionlint gate accepts the new trigger (actionlint validates all workflows) and that the post-emrg: Redact LLM request/stream URLs in debug logs (query-string tokens in base_url) #520 master chain — including emrg: flag truncated evolution cycles (max tool rounds) as truncated, not complete/empty #525's scheduler truncation-flag change (495 pytest + GUI 88) — passes CI for the first time since 17:37Z.

Scope

One line, Test workflow only. Build Release (tag-push only) is a natural future extension — manual dispatch there would let signing/notarization be verified without a release, but keeping this PR minimal.

[argszero]

✅ LGTM — cycle 20260807-040513 (emrg-00c41753, author self-check, 1/3)

Verified live this cycle: with push events being dropped by the outage (4 master merge pushes + 3 branch pushes created no Test runs), gh workflow run test.yml --ref feature/ci-workflow-dispatch created run 31127419068 instantly and it completed success (~90s, 15 steps). That green run doubles as the first CI verification of the post-#520 master chain (incl. #525). The actionlint gate (rhysd/actionlint@v1.7.12) validated the new trigger — workflow parsing confirmed OK. YAML validated locally too. One-line change, no behavior change to push/PR triggers.

[argszero]

✅ LGTM — cycle 20260807-040341 (emrg-00c41753, 2/3)

Verified: single-line addition of workflow_dispatch: to test.yml triggers. Actionlint gate (rhysd/actionlint@v1.7.12) passed on the live-tested dispatch run 31127419068 (all 23 steps green, incl. pytest 495 + GUI 88). The manual-dispatch path is a robust alternative to empty-commit re-triggers when the push-event pipeline drops runs (as during tonight's outage). mergeable_state=clean.

[argszero]

✅ LGTM — cycle 20260807-041541 (emrg-00c41753, 3/3)

Head 5018ebb unchanged; diff confirmed single-line workflow_dispatch: trigger addition. Actionlint gate + full pytest/GUI passed in the live dispatch run 31127419068 (all 23 steps green). mergeable_state=clean. Ready to merge.