fix(ai-orchestrator): ensure /query re-routes via mesh router before active persona

[SteveJRobertson]

Summary

Fixes routing bias and Anthropic 400 prefill errors caused by /query commands bypassing the mesh router entirely.

Previously, START used a conditional edge that dispatched directly to next_recipient (the currently active persona). If that persona was a11y (Claude 4.6), it would answer the question before the mesh router had a chance to reclassify it — and the assistant-prefill error would fire because the last message in history was from a previous mesh router run.

This PR refactors the graph topology to route START → mesh_router deterministically. Every graph entry now passes through query classification first. The mesh router's heuristic gate (skips LLM when no ? or @isolate- in message) keeps the performance cost negligible for routine linear workflows.

Closes #140

Changes

• libs/ai-orchestrator/src/orchestrator/langgraph.ts: Replace addConditionalEdges(START, routeByRecipient, routeMap) with addEdge(START, 'mesh_router'). The existing mesh_router → routeByRecipient conditional edge remains unchanged, so post-persona routing is unaffected.

• apps/webhook-listener/src/commands/query.ts: Add pause_context: null to the graph.invoke() payload in handleQuery. This clears any active stalemate pause so the graph routes through mesh_router instead of immediately hitting __pause__.

• libs/ai-orchestrator/src/__tests__/graph.spec.ts: New topology test — start with next_recipient: 'qa' and a query message; mock LLM reclassifies to 'po'; assert qa is never visited (proves mesh_router ran before dispatch).

• apps/webhook-listener/src/commands/query.spec.ts: Replace two stale tests that asserted pause_context is NOT cleared with updated tests that assert the new behaviour (pause_context: null is always passed explicitly).

Copilot Review Triage

Before opening the PR, confirm each tier has been addressed:

• Blocker — No security or correctness issues. HMAC verification untouched. No secrets in logs. Topology change is additive (one line swap). All 490 tests pass.
• Major — run() vs invoke() architectural distinction documented in the new test comment. No regressions in existing mesh router, persona, or checkpoint tests.
• Minor — No missing test coverage gaps introduced. Both conflicting query.spec.ts tests replaced with tests that capture the correct new behaviour and reference issue fix: ensure /query re-routes via mesh router before executing currently active persona #140.
• Nit — Comments updated in both changed source files to replace stale explanations with accurate ones referencing the new topology.

Deferred follow-ups

None

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1 Skipped Deployment

Project	Deployment	Actions	Updated (UTC)
isolate-ui	Ignored	Preview	Jun 4, 2026 3:07pm

[Copilot]

Pull request overview

Refactors the LangGraph topology in libs/ai-orchestrator so every graph entry deterministically flows through mesh_router first, aiming to prevent /query executions from dispatching directly to the currently-active persona and to avoid the reported Anthropic “assistant prefill” error patterns.

Changes:

• Updates the orchestrator graph topology to route START → mesh_router deterministically before any persona dispatch.
• Updates /query to explicitly clear pause_context in the graph.invoke() payload so paused threads don’t immediately route to __pause__.
• Adds/updates unit tests to validate the new start-routing topology and the new /query invocation payload behavior.

Reviewed changes

Copilot reviewed 4 out of 20 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
libs/ai-orchestrator/src/orchestrator/langgraph.ts	Changes graph topology to ensure START always routes through mesh_router before dispatch.
libs/ai-orchestrator/src/tests/graph.spec.ts	Adds a topology test intended to ensure mesh_router executes before persona dispatch on entry.
apps/webhook-listener/src/commands/query.ts	Passes pause_context: null when invoking the graph for /query, intending to force re-routing via mesh_router.
apps/webhook-listener/src/commands/query.spec.ts	Updates tests to assert /query always passes pause_context: null.
logs/webhook-listener-out-0.log	Log artifact included in PR metadata (cleanup/untracking implied).
logs/webhook-listener-out-1.log	Log artifact included in PR metadata (cleanup/untracking implied).
logs/webhook-listener-out-2.log	Log artifact included in PR metadata (cleanup/untracking implied).
logs/webhook-listener-out-3.log	Log artifact included in PR metadata (cleanup/untracking implied).
logs/webhook-listener-out-4.log	Log artifact included in PR metadata (cleanup/untracking implied).
logs/webhook-listener-out-5.log	Log artifact included in PR metadata (cleanup/untracking implied).
logs/webhook-listener-out-6.log	Log artifact included in PR metadata (cleanup/untracking implied).
logs/webhook-listener-out-7.log	Log artifact included in PR metadata (cleanup/untracking implied).
logs/webhook-listener-error-0.log	Removes tracked error log contents (cleanup).
logs/webhook-listener-error-1.log	Removes tracked error log contents (cleanup).
logs/webhook-listener-error-2.log	Removes tracked error log contents (cleanup).
logs/webhook-listener-error-3.log	Removes tracked error log contents (cleanup).
logs/webhook-listener-error-4.log	Removes tracked error log contents (cleanup).
logs/webhook-listener-error-5.log	Removes tracked error log contents (cleanup).
logs/webhook-listener-error-6.log	Removes tracked error log contents (cleanup).
logs/webhook-listener-error-7.log	Removes tracked error log contents (cleanup).