fix: validate routing models against discovery

[guillaumegay13]

---

Summary by cubic

Enforces that routing selections only use models discovered for the agent and removes pricing/prefix-based fallbacks. Improves cleanup on provider removal while preserving native-only picks when an API key remains. Related to #1203.

• Bug Fixes
  • Validate setOverride/setFallbacks against discovery; reject missing models with BadRequestException.
  • getEffectiveModel: use the override only if it’s discovered; otherwise fall back to auto; remove pricing/provider-prefix heuristics.
  • On provider removal, clear overrides/fallbacks tied to the removed provider or its removed cached_models, and notify; keep native-only models if another active auth (e.g., API key) for the same provider remains.
  • Discovery: do not synthesize api-key models from pricing/OpenRouter when native discovery returns empty; subscription providers are still supplemented with known subscription models.
  • setFallbacks: de-duplicate inputs, exclude the current override, and return the cleaned list.

^{Written for commit 7d0f40e. Summary will update on new commits.}

Related to #1203

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.48%. Comparing base (0786a68) to head (7d0f40e).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1206   +/-   ##
=======================================
  Coverage   98.48%   98.48%           
=======================================
  Files          94       94           
  Lines        7605     7605           
  Branches     2901     2901           
=======================================
  Hits         7490     7490           
  Misses         88       88           
  Partials       27       27           

Flag	Coverage Δ
frontend	98.73% <ø> (ø)
plugin	95.89% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[cubic-dev-ai]

2 issues found across 4 files

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="packages/backend/src/routing/routing.service.ts">

<violation number="1" location="packages/backend/src/routing/routing.service.ts:182">
P2: `removedModels` is collected from all `unsupported` records, but should only include models from providers in `removedProviders`. If a provider is still active via a different auth type, its models from the unsupported subscription record will be incorrectly flagged for tier-assignment removal.</violation>
</file>

<file name="packages/backend/src/routing/model-discovery/model-discovery.service.spec.ts">

<violation number="1" location="packages/backend/src/routing/model-discovery/model-discovery.service.spec.ts:884">
P2: The comment says subscription models "are still supplemented" but the assertion `toBeGreaterThanOrEqual(0)` is a tautology — it passes even when the result is empty (i.e., no supplementing occurred). If the intent is to verify fallback models are returned, use `toBeGreaterThan(0)` or assert on specific model IDs.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[guillaumegay13]

@brunobuddy merge conflicts resolved.