feat(onboarding): verify Test connection without a model id (#792)

[lifelmy]

Problem

Fixes #792.

In Settings → Model services, the Test connection button calls the onboarding.provider.probe RPC, whose underlying probe_llm_provider() hard-requires a model id (an empty model raises ValueError). That is a chicken-and-egg bind for a new user: you cannot know which models a provider serves until you can list them, but the model list is only fetched after the connection verifies — and the connection cannot be verified without already supplying a valid model id.

Change

When the model field is empty, connectivity is now verified through the model-list endpoint (GET /v1/models via the existing discover_provider_models()) instead of a one-token chat completion — exactly the behavior the issue proposes.

• Backend (gateway/rpc_onboarding.py): onboarding.provider.probe branches on the model field. With a model it runs the usual usage-accounted chat probe; with an empty model it calls a new _connectivity_probe_via_discovery() helper that runs discover_provider_models() and maps the listing outcome (ok / failureKind / detail) back onto the frozen probe envelope. The chat-only timing fields (latencyMs, firstResponseMs, totalMs) stay at their never-reached-the-network sentinels since no chat round-trip happened. An ok listing that simply returns nothing still counts as reachable (the credentials verified). The wire contract is unchanged.
• Frontend (useSetupCatalog.ts): for a draft primary-provider config, an empty model is no longer treated as a missing required field, so the Test connection button is enabled and probes with no model param. Stored/draft profile probes go through onboarding.llmProfile[.draft].probe, which still resolves a concrete deployment model, so those keep requiring a model.

Testing (all run locally, real execution)

• uv run ruff check src tests → all checks passed
• uv run pytest -q tests/test_gateway/test_rpc_onboarding.py tests/test_contracts tests/test_onboarding → 1196 passed, 4 skipped
  • new: test_provider_probe_without_model_verifies_via_model_list, test_provider_probe_without_model_reports_auth_failure
• uv run pytest -q tests/test_cli/test_models_probe.py → 12 passed; uv run pytest -q tests/test_onboarding/test_provider_probe.py → passed
• uv run mypy src/opensquilla/gateway/rpc_onboarding.py → no issues
• npx vitest run on useSetupCatalog.privacy.test.ts + useSetupProviderForm.test.ts (232 passed) and SetupProviderPanel.test.ts + SetupProviderCredentialCard.test.ts (123 passed); updated the privacy suite's model-less probe expectations
• npm run build (Web UI artifact verified + staged), npm run typecheck (all guards passed), uv build --wheel → built opensquilla-0.5.4-py3-none-any.whl

Notes

I use a coding assistant to help implement, and I review and take responsibility for the final change. Opened as a draft for maintainer review; happy to adjust the surface (e.g. keep the button enabled but relabel it, or gate the fallback behind a capability flag) if you prefer a different shape.

[lifelmy]

Current follow-up on head 64f14dcdfa after refreshing upstream/main (f9467234b5; branch is 0 behind / 6 ahead): the PR remains mergeable, and the implementation-specific suites pass locally.

Verification:

• .venv/bin/pytest -q tests/test_gateway/test_rpc_onboarding.py → 72 passed
• cd opensquilla-webui && bun run test:unit -- src/composables/setup/useSetupCatalog.privacy.test.ts → 175 passed

The remaining failed GitHub check is unrelated to this PR's onboarding diff: Windows high-risk (core) completed 6,947 tests successfully and then tests/test_process_tree.py::test_windows_gateway_crash_kills_job_and_reconcile_removes_stale_row timed out at its 15-second worker.wait() limit. CI result only mirrors that failure. I attempted gh run rerun 33724721382 --failed again, but GitHub rejected it because this contributor account lacks repository admin rights.

A maintainer/admin rerun of failed jobs for run 33724721382 is still needed to clear the transient Windows gate.

[lifelmy]

Refreshed this PR onto the latest upstream/main (3f92428e); current head is 31118a7d. The merge completed without manual conflict edits and preserved the model-id-free connection verification paths.

Verification on the refreshed head:

• .venv/bin/pytest -q tests/test_onboarding tests/test_github_issue_link_sync.py -> 1001 passed, 4 skipped
• npm --prefix opensquilla-webui run test:unit -- src/composables/setup/useSetupCatalog.privacy.test.ts -> 175 passed
• focused ruff check -> passed
• git diff --check upstream/main...HEAD -> passed

The push superseded the prior CI run containing the unrelated Windows core timeout. GitHub reports the refreshed branch as mergeable; its new CI jobs are running.

[lifelmy]

Refreshed this PR onto the latest upstream/main (4535029); new head is 33de521. The branch was 1 commit behind and merged cleanly without manual conflict edits. Verification: backend onboarding/RPC/issue-link suites passed (1073 passed, 4 skipped); WebUI privacy suite passed (175 passed); focused ruff and git diff --check passed.

[lifelmy]

Task A CI follow-up (2026-09-05): the completed Windows recovery-migration shard had one failure in test_aggregator_partial_output_idle_timeout_is_replaced_by_fixed_aggregator[tool], outside this PR's onboarding/WebUI diff; the other 4,251 tests in that phase passed. I re-ran the exact failing test 5 times locally and all 5 passed. The PR-focused backend run passed 75 tests (including onboarding and the failing ensemble test), WebUI privacy passed 175 tests, focused ruff and git diff --check passed. I attempted to rerun failed GitHub jobs, but GitHub requires repository admin rights for this run, so the failed check remains maintainer-controlled.

[lifelmy]

Task A refresh (2026-09-05): fetched latest upstream/main at 770ff387c6, merged it without conflicts, and pushed head cfad87c0d7. The two new base commits touch provider ensemble/runtime and WebUI toast-host paths; this PR's model-less Test connection behavior remains intact.

Verification on the refreshed head:

• uv run pytest -q tests/test_gateway/test_rpc_onboarding.py tests/test_onboarding/test_flow_provider_verify.py -> 96 passed
• npm --prefix opensquilla-webui run test:unit -- src/composables/setup/useSetupCatalog.privacy.test.ts -> 175 passed
• focused uv run ruff check -> passed
• git diff --check upstream/main...HEAD -> passed

No new comments/reviews or unresolved review threads.

[lifelmy]

Refreshed this branch onto latest upstream/main (1663b1a); new head is e3c1716. The one-commit base update merged without conflicts, preserving the onboarding Test connection behavior. Verification: backend onboarding suite 72 passed; WebUI privacy Vitest suite 175 passed; focused Ruff and git diff --check passed.

[lifelmy]

Task A refresh: merged latest upstream/main (846bbc6b) without conflicts; new head is d7a086ae8. The model-id-free Test connection behavior remains covered. Verification: full onboarding tests passed (984 passed, 4 skipped; one existing deprecation warning), focused Ruff passed, WebUI privacy Vitest passed (175 tests), and git diff --check upstream/main...HEAD passed.

[lifelmy]

Task A refresh: merged latest upstream/main (085bfed00d) without conflicts; new head is 7416f76f13. The upstream change consolidates settings and durable turn admission, and the model-id-free Test connection behavior remains intact. Verification: backend onboarding/provider verification tests passed (96), focused Ruff passed, WebUI privacy Vitest passed (175), and git diff --check upstream/main...HEAD passed.