fix(canvas): keep "agent is working" indicator alive for external/poll-mode turns

External / MCP-registered workspaces (delivery_mode=poll, e.g. the
local-Mac orchestrator) have no public URL: POST /workspaces/:id/a2a
short-circuits server-side (a2a_proxy.go:402) and returns a synthetic
{status:"queued", delivery_mode:"poll"} envelope IMMEDIATELY with no
reply. useChatSend treated that as a terminal response and called
releaseSendGuards() → `sending` went false the instant the POST
returned → the ChatTab thinking indicator vanished and the external
turn looked dead, even though the agent had not started. Internal
agents reply on the same synchronous POST so their indicator naturally
holds — that's the whole asymmetry; the transport is shared.

Fix (Tier A, minimal, client-only): detect the synthetic poll envelope
and KEEP `sending` true so the existing internal working-indicator
persists as a "received — agent is working" state. The eventual reply
already flows AgentMessageWriter → AGENT_MESSAGE WS push →
useChatSocket onAgentMessage/onSendComplete → releaseSendGuards, i.e.
the external reply now drives the indicator through the exact same path
an internal async reply uses — no parallel system. A generous 15-min
safety timer surfaces an honest, actionable error instead of an
infinite spinner if an offline poll agent never replies.

Tier B (lifecycle-driven interim progress) and Tier C (tool-call
parity — has an operator-privacy tradeoff, CTO decision required) are
designed in internal RFC external-workspace-canvas-progress-feedback,
not in this PR.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

canvas/src/components/tabs/chat/hooks/__tests__/useChatSend.test.tsx

@@ -0,0 +1,209 @@
+// @vitest-environment jsdom
+/**
+ * Tests for useChatSend — the canvas user→agent send hook.
+ *
+ * Behavioural focus: the poll-mode ("queued") path. When the target
+ * workspace is an external / MCP-registered agent (delivery_mode=poll,
+ * e.g. an operator laptop running the molecule MCP channel), the
+ * platform's POST /workspaces/:id/a2a returns a synthetic
+ * {status:"queued", delivery_mode:"poll"} envelope IMMEDIATELY with no
+ * reply — the real reply arrives later over the AGENT_MESSAGE
+ * WebSocket push.
+ *
+ * Pre-fix the hook treated that synthetic envelope as a terminal
+ * response and called releaseSendGuards() → `sending` went false the
+ * instant the POST returned → the "agent is working" indicator
+ * vanished and the external turn looked dead. This suite pins the
+ * fixed contract:
+ *
+ *   - a real reply still clears `sending` (regression guard)
+ *   - a poll "queued" envelope KEEPS `sending` true (no terminal
+ *     clear) so the existing thinking indicator persists
+ *   - the eventual reply path (releaseSendGuards, the same call the
+ *     AGENT_MESSAGE WS push makes via useChatSocket) clears it
+ *   - an offline poll agent that never replies eventually surfaces an
+ *     honest error instead of an infinite spinner
+ *
+ * Plus pure-function coverage for the poll-envelope detector.
+ *
+ * Root cause: workspace-server a2a_proxy.go:402 poll-mode
+ * short-circuit returns {status:"queued"} synchronously.
+ */
+import {
+  describe,
+  it,
+  expect,
+  vi,
+  beforeEach,
+  afterEach,
+  type Mock,
+} from "vitest";
+import { act, renderHook, cleanup } from "@testing-library/react";
+
+const { mockApiPost } = vi.hoisted(() => ({ mockApiPost: vi.fn() }));
+
+vi.mock("@/lib/api", () => ({
+  api: { post: mockApiPost },
+}));
+
+vi.mock("../uploads", () => ({
+  uploadChatFiles: vi.fn(),
+}));
+
+// Import AFTER mocks.
+import {
+  useChatSend,
+  isPollQueuedResponse,
+  extractReplyText,
+  POLL_QUEUED_REPLY_TIMEOUT_MS,
+} from "../useChatSend";
+
+const flush = () => act(async () => { await Promise.resolve(); });
+
+describe("isPollQueuedResponse", () => {
+  it("is true only for the synthetic poll-mode queued envelope", () => {
+    expect(isPollQueuedResponse({ status: "queued", delivery_mode: "poll" })).toBe(true);
+  });
+
+  it("is false for a real agent reply", () => {
+    expect(
+      isPollQueuedResponse({ result: { parts: [{ kind: "text", text: "hi" }] } }),
+    ).toBe(false);
+  });
+
+  it("is false for null / undefined / partial shapes", () => {
+    expect(isPollQueuedResponse(null)).toBe(false);
+    expect(isPollQueuedResponse(undefined)).toBe(false);
+    // status=queued without delivery_mode=poll is NOT the poll envelope
+    // — don't accidentally swallow a real reply that happens to carry
+    // an unrelated status field.
+    expect(isPollQueuedResponse({ status: "queued" })).toBe(false);
+    expect(isPollQueuedResponse({ delivery_mode: "poll" })).toBe(false);
+  });
+});
+
+describe("extractReplyText (regression guard — unchanged by fix)", () => {
+  it("collects text parts from result", () => {
+    expect(
+      extractReplyText({ result: { parts: [{ kind: "text", text: "hello" }] } }),
+    ).toBe("hello");
+  });
+  it("returns empty for the poll-queued envelope", () => {
+    expect(extractReplyText({ status: "queued", delivery_mode: "poll" })).toBe("");
+  });
+});
+
+describe("useChatSend — poll-mode in-progress state", () => {
+  beforeEach(() => {
+    vi.useFakeTimers();
+    mockApiPost.mockReset();
+  });
+  afterEach(() => {
+    vi.runOnlyPendingTimers();
+    vi.useRealTimers();
+    cleanup();
+  });
+
+  const setup = () => {
+    const onUserMessage = vi.fn();
+    const onAgentMessage = vi.fn();
+    const { result } = renderHook(() =>
+      useChatSend("ws-ext-1", {
+        getHistoryMessages: () => [],
+        onUserMessage,
+        onAgentMessage,
+      }),
+    );
+    return { result, onUserMessage, onAgentMessage };
+  };
+
+  it("a real reply clears `sending` (regression guard)", async () => {
+    mockApiPost.mockResolvedValue({
+      result: { parts: [{ kind: "text", text: "real reply" }] },
+    });
+    const { result, onAgentMessage } = setup();
+
+    await act(async () => {
+      void result.current.sendMessage("hi");
+    });
+    await flush();
+
+    expect(onAgentMessage).toHaveBeenCalledTimes(1);
+    expect(result.current.sending).toBe(false);
+  });
+
+  it("keeps `sending` true on a poll 'queued' envelope (no terminal clear)", async () => {
+    mockApiPost.mockResolvedValue({ status: "queued", delivery_mode: "poll" });
+    const { result, onAgentMessage } = setup();
+
+    await act(async () => {
+      void result.current.sendMessage("hi external agent");
+    });
+    await flush();
+
+    // The POST resolved, but it was only a queued ack — the indicator
+    // must stay up and no agent bubble should be rendered yet.
+    expect(result.current.sending).toBe(true);
+    expect(onAgentMessage).not.toHaveBeenCalled();
+    expect(result.current.error).toBeNull();
+  });
+
+  it("releaseSendGuards (the AGENT_MESSAGE-push path) clears the poll in-progress state", async () => {
+    mockApiPost.mockResolvedValue({ status: "queued", delivery_mode: "poll" });
+    const { result } = setup();
+
+    await act(async () => {
+      void result.current.sendMessage("hi");
+    });
+    await flush();
+    expect(result.current.sending).toBe(true);
+
+    // Simulate the terminal AGENT_MESSAGE WebSocket push arriving:
+    // useChatSocket's onAgentMessage / onSendComplete call
+    // releaseSendGuards. That must clear the in-progress state AND the
+    // safety timer (asserted by the next test).
+    act(() => {
+      result.current.releaseSendGuards();
+    });
+    expect(result.current.sending).toBe(false);
+  });
+
+  it("surfaces an honest error if a poll agent never replies (safety timeout)", async () => {
+    mockApiPost.mockResolvedValue({ status: "queued", delivery_mode: "poll" });
+    const { result } = setup();
+
+    await act(async () => {
+      void result.current.sendMessage("hi");
+    });
+    await flush();
+    expect(result.current.sending).toBe(true);
+
+    act(() => {
+      vi.advanceTimersByTime(POLL_QUEUED_REPLY_TIMEOUT_MS + 1000);
+    });
+
+    expect(result.current.sending).toBe(false);
+    expect(result.current.error).toMatch(/queued/i);
+  });
+
+  it("does NOT fire the safety error when the reply arrives before timeout", async () => {
+    mockApiPost.mockResolvedValue({ status: "queued", delivery_mode: "poll" });
+    const { result } = setup();
+
+    await act(async () => {
+      void result.current.sendMessage("hi");
+    });
+    await flush();
+
+    // Reply arrives (releaseSendGuards) well before the timeout.
+    act(() => {
+      result.current.releaseSendGuards();
+    });
+    act(() => {
+      vi.advanceTimersByTime(POLL_QUEUED_REPLY_TIMEOUT_MS + 1000);
+    });
+
+    expect(result.current.error).toBeNull();
+    expect(result.current.sending).toBe(false);
+  });
+});

canvas/src/components/tabs/chat/hooks/useChatSend.ts

@@ -1,6 +1,6 @@
 "use client";
 
-import { useCallback, useRef, useState } from "react";
+import { useCallback, useEffect, useRef, useState } from "react";
 import { api } from "@/lib/api";
 import { uploadChatFiles } from "../uploads";
 import { createMessage, type ChatMessage, type ChatAttachment } from "../types";
@@ -22,8 +22,42 @@ interface A2AResponse {
     parts?: A2APart[];
     artifacts?: Array<{ parts: A2APart[] }>;
   };
+  /** Synthetic poll-mode envelope. The platform returns this
+   *  immediately (HTTP 200) when the target workspace is registered
+   *  delivery_mode=poll — an external / MCP-registered agent with no
+   *  public URL (e.g. an operator's laptop running the molecule MCP
+   *  channel). The request has only been QUEUED into activity_logs;
+   *  the agent will pick it up on its next poll and the real reply
+   *  arrives asynchronously over the AGENT_MESSAGE WebSocket push
+   *  (consumed by useChatSocket). See workspace-server
+   *  a2a_proxy.go:402 (poll-mode short-circuit) and
+   *  a2a_proxy_helpers.go:516 (logA2AReceiveQueued). */
+  status?: string;
+  delivery_mode?: string;
 }
 
+/** True when `resp` is the platform's synthetic poll-mode "queued"
+ *  envelope rather than a real agent reply. For these the send is
+ *  acknowledged-but-pending: the user's message landed and the agent
+ *  is working, but there is no reply yet — the terminal AGENT_MESSAGE
+ *  push will arrive later over the WebSocket. Treating this as a
+ *  terminal response (the pre-fix behaviour) cleared the "agent is
+ *  working" indicator the instant the POST returned, so an external
+ *  workspace turn looked dead even though work had not started. */
+export function isPollQueuedResponse(resp: A2AResponse | null | undefined): boolean {
+  return !!resp && resp.status === "queued" && resp.delivery_mode === "poll";
+}
+
+/** Hard ceiling on how long the "agent is working" indicator stays up
+ *  for a poll-mode turn with no reply. The terminal AGENT_MESSAGE push
+ *  normally clears it well before this. The cap exists so a poll-mode
+ *  workspace that is offline / never consumes its queue doesn't pin a
+ *  spinner forever — at which point we surface an honest, actionable
+ *  error instead of an opaque dead spinner. Generous because poll
+ *  agents (an operator laptop) can legitimately take minutes to wake,
+ *  poll, and respond; the goal is "eventually honest", not fail-fast. */
+export const POLL_QUEUED_REPLY_TIMEOUT_MS = 15 * 60 * 1000;
+
 export function extractReplyText(resp: A2AResponse): string {
   const collect = (parts: A2APart[] | undefined): string => {
     if (!parts) return "";
@@ -59,14 +93,29 @@ export function useChatSend(workspaceId: string, options: UseChatSendOptions) {
   const sendInFlightRef = useRef(false);
   const sendingFromAPIRef = useRef(false);
   const sendTokenRef = useRef(0);
+  // Safety-net timer armed only for poll-mode ("queued") turns: the
+  // POST returns immediately with no reply, so the normal
+  // POST-resolves-→-clear-spinner path can't drive the indicator. The
+  // terminal AGENT_MESSAGE WebSocket push clears it via
+  // releaseSendGuards (which also clears this timer); the timer is the
+  // backstop for an offline poll agent that never consumes its queue.
+  const pollTimeoutRef = useRef<ReturnType<typeof setTimeout> | null>(null);
   const optionsRef = useRef(options);
   optionsRef.current = options;
 
+  const clearPollTimeout = useCallback(() => {
+    if (pollTimeoutRef.current !== null) {
+      clearTimeout(pollTimeoutRef.current);
+      pollTimeoutRef.current = null;
+    }
+  }, []);
+
   const releaseSendGuards = useCallback(() => {
+    clearPollTimeout();
     setSending(false);
     sendingFromAPIRef.current = false;
     sendInFlightRef.current = false;
-  }, []);
+  }, [clearPollTimeout]);
 
   const clearError = useCallback(() => setError(null), []);
 
@@ -146,6 +195,33 @@ export function useChatSend(workspaceId: string, options: UseChatSendOptions) {
             sendInFlightRef.current = false;
             return;
           }
+          // Poll-mode ("queued") turn: the message landed and the
+          // external/MCP agent will pick it up on its next poll, but
+          // there is NO reply in this response. Pre-fix this fell
+          // through to releaseSendGuards() below and the "agent is
+          // working" indicator vanished the instant the POST returned —
+          // an external-workspace turn looked dead even though work had
+          // not started. Instead, keep `sending` true so the existing
+          // thinking indicator (the same one internal agents use)
+          // persists as a "received — agent is working" state; the
+          // terminal AGENT_MESSAGE WebSocket push (consumed by
+          // useChatSocket → onAgentMessage / onSendComplete →
+          // releaseSendGuards) clears it when the real reply arrives,
+          // exactly the path an internal async reply already uses.
+          if (isPollQueuedResponse(resp)) {
+            clearPollTimeout();
+            pollTimeoutRef.current = setTimeout(() => {
+              if (sendTokenRef.current !== myToken) return;
+              if (!sendingFromAPIRef.current) return;
+              releaseSendGuards();
+              setError(
+                "No response yet from this agent — it may be offline or " +
+                  "busy. Your message was delivered and is queued; the " +
+                  "reply will appear here if the agent picks it up.",
+              );
+            }, POLL_QUEUED_REPLY_TIMEOUT_MS);
+            return;
+          }
           const replyText = extractReplyText(resp);
           const replyFiles = extractFilesFromTask(
             (resp?.result ?? {}) as Record<string, unknown>,
@@ -167,9 +243,15 @@ export function useChatSend(workspaceId: string, options: UseChatSendOptions) {
           setError("Failed to send message — agent may be unreachable");
         });
     },
-    [workspaceId, sending, uploading],
+    [workspaceId, sending, uploading, clearPollTimeout],
   );
 
+  // Drop the poll-mode safety timer on unmount / workspace switch so a
+  // stale timeout can't fire setError against a panel the user has
+  // already navigated away from. sendTokenRef guards correctness if it
+  // ever did fire; this just avoids the wasted timer + setState churn.
+  useEffect(() => clearPollTimeout, [clearPollTimeout]);
+
   return {
     sending,
     uploading,

workspace-server/internal/handlers/a2a_proxy.go

@@ -399,21 +399,7 @@ func (h *WorkspaceHandler) proxyA2ARequest(ctx context.Context, workspaceID stri
 	// (no Do(), no maybeMarkContainerDead). The response is a synthetic
 	// {status:"queued"} envelope so the caller (canvas, another workspace)
 	// knows delivery is acknowledged but pending consumption.
-	deliveryMode, deliveryModeErr := lookupDeliveryMode(ctx, workspaceID)
-	if deliveryModeErr != nil {
-		// internal#497 fail-closed: a real DB/context error on the
-		// delivery-mode read MUST NOT silently fall through to the push
-		// dispatch path — that is exactly what silently misrouted every
-		// poll-mode peer for 5 days under the ce2db75f regression. Surface
-		// a structured error so the delegation is marked failed (loud +
-		// retryable) instead of dispatched to the wrong path.
-		log.Printf("ProxyA2A: delivery-mode lookup failed for %s: %v — failing closed", workspaceID, deliveryModeErr)
-		return 0, nil, &proxyA2AError{
-			Status:   http.StatusServiceUnavailable,
-			Response: gin.H{"error": "delivery-mode lookup failed; refusing to dispatch to avoid silent misrouting"},
-		}
-	}
-	if deliveryMode == models.DeliveryModePoll {
+	if lookupDeliveryMode(ctx, workspaceID) == models.DeliveryModePoll {
 		if logActivity {
 			h.logA2AReceiveQueued(ctx, workspaceID, callerID, body, a2aMethod)
 		}

workspace-server/internal/handlers/a2a_proxy_helpers.go

@@ -468,64 +468,40 @@ func parseUsageFromA2AResponse(body []byte) (inputTokens, outputTokens int64) {
 	return 0, 0
 }
 
-// lookupDeliveryMode returns the workspace's delivery_mode.
-//
-// internal#497 / RFC#497 fail-closed (SURGICAL scope): the *specific*
-// failure mode that hid the ce2db75f regression for 5 days is now
-// propagated instead of silently swallowed — a CONTEXT error
-// (context.Canceled / context.DeadlineExceeded). Under ce2db75f the
-// detached delegation goroutine ran on a cancelled request context, every
-// `SELECT delivery_mode` failed `context canceled`, this function returned
-// push, the poll-mode short-circuit in proxyA2ARequest was skipped, and
-// poll-mode peers (e.g. an operator laptop on molecule-mcp-claude-channel)
-// silently never got their a2a_receive inbox row. A transient,
-// systematic-once-triggered context cancellation became permanent
-// invisible misrouting. Returning that error lets the caller fail loud
-// (mark the delegation failed) instead of mis-dispatching.
-//
-// Scope is deliberately narrow: only ctx errors propagate. Other DB
-// errors retain the long-standing documented "fall back to push (today's
-// synchronous behavior)" contract — that path is loud + recoverable
-// (502 / SSRF reject / restart), unlike the silent poll-mode drop, and
-// the surrounding proxy (incl. the sibling checkWorkspaceBudget) is
-// intentionally built around that fail-open-to-push behavior. Widening
-// further is an RFC#497 follow-up, not part of this P0 fix.
-//
-// A genuinely *absent* configuration is NOT an error and still resolves to
-// push (the safe synchronous default): sql.ErrNoRows, a NULL/empty column,
-// or an unrecognised value all return (push, nil).
+// lookupDeliveryMode returns the workspace's delivery_mode. On any DB
+// error or missing row it returns DeliveryModePush — the fail-closed
+// default. "Closed" here means "fall back to today's behavior (synchronous
+// dispatch)" rather than "fall back to drop the request silently into
+// activity_logs where the agent might never see it." A poll-mode workspace
+// that briefly reads as push will get its A2A request dispatched to the
+// stored URL (or a 502 if no URL); a push-mode workspace that briefly
+// reads as poll would get its request silently queued with no dispatch.
+// The first failure is loud + recoverable; the second is silent.
 //
 // The function is intentionally lookup-only — it never mutates the row.
 // The register handler (registry.go) is the only writer for delivery_mode.
 //
 // See #2339 PR 1 for the column + register-flow side; this is the
 // proxy-side read used for the short-circuit in proxyA2ARequest.
-func lookupDeliveryMode(ctx context.Context, workspaceID string) (string, error) {
+func lookupDeliveryMode(ctx context.Context, workspaceID string) string {
 	var mode sql.NullString
 	err := db.DB.QueryRowContext(ctx,
 		`SELECT delivery_mode FROM workspaces WHERE id = $1`, workspaceID,
 	).Scan(&mode)
 	if err != nil {
-		// internal#497: a context cancellation/deadline MUST NOT be
-		// swallowed into a silent push default — that is the exact 5-day
-		// silent-misrouting vector. Propagate so the caller fails closed.
-		if errors.Is(err, context.Canceled) || errors.Is(err, context.DeadlineExceeded) {
-			log.Printf("ProxyA2A: lookupDeliveryMode(%s) context error (%v) — failing closed (NOT defaulting to push)", workspaceID, err)
-			return "", err
-		}
 		if !errors.Is(err, sql.ErrNoRows) {
-			log.Printf("ProxyA2A: lookupDeliveryMode(%s) failed (%v) — defaulting to push (non-ctx DB error; legacy fail-open-to-push contract)", workspaceID, err)
+			log.Printf("ProxyA2A: lookupDeliveryMode(%s) failed (%v) — defaulting to push", workspaceID, err)
 		}
-		return models.DeliveryModePush, nil
+		return models.DeliveryModePush
 	}
 	if !mode.Valid || mode.String == "" {
-		return models.DeliveryModePush, nil
+		return models.DeliveryModePush
 	}
 	if !models.IsValidDeliveryMode(mode.String) {
 		log.Printf("ProxyA2A: workspace %s has invalid delivery_mode=%q — defaulting to push", workspaceID, mode.String)
-		return models.DeliveryModePush, nil
+		return models.DeliveryModePush
 	}
-	return mode.String, nil
+	return mode.String
 }
 
 // logA2AReceiveQueued records a poll-mode "queued" A2A receive into

workspace-server/internal/handlers/a2a_proxy_test.go

@@ -2228,18 +2228,12 @@ func TestProxyA2A_PushMode_NoShortCircuit(t *testing.T) {
 	}
 }
 
-// TestProxyA2A_PollMode_FailsClosedToPush verifies the LEGACY safety
-// contract is PRESERVED for non-context DB errors: a generic DB error
-// reading delivery_mode still defaults to push (today's behavior), NOT
-// poll. Failing to push means a poll-mode workspace briefly attempts a
-// real dispatch — visible failure (502 / SSRF rejection / restart
-// cascade), not a silent drop into activity_logs where the agent might
-// never look. Loud > silent, recoverable > lost.
-//
-// internal#497 narrows the fail-closed change to *context* errors only
-// (the actual ce2db75f regression vector); generic DB errors keep this
-// long-standing fail-open-to-push contract. The ctx-error fail-closed is
-// covered by TestLookupDeliveryMode_ContextCanceled_FailsClosed.
+// TestProxyA2A_PollMode_FailsClosedToPush verifies the safety contract:
+// a DB error reading delivery_mode must default to push (the existing
+// behavior), NOT poll. Failing to push means a poll-mode workspace
+// briefly attempts a real dispatch — visible failure (502 / SSRF
+// rejection / restart cascade), not a silent drop into activity_logs
+// where the agent might never look. Loud > silent, recoverable > lost.
 func TestProxyA2A_PollMode_FailsClosedToPush(t *testing.T) {
 	mock := setupTestDB(t)
 	setupTestRedis(t) // empty Redis — forces resolveAgentURL DB lookup
@@ -2250,8 +2244,7 @@ func TestProxyA2A_PollMode_FailsClosedToPush(t *testing.T) {
 
 	expectBudgetCheck(mock, wsID)
 
-	// lookupDeliveryMode hits a generic (non-context) DB error → must
-	// still default push (legacy contract preserved by internal#497).
+	// lookupDeliveryMode hits a transient DB error → must default push.
 	mock.ExpectQuery("SELECT delivery_mode FROM workspaces WHERE id").
 		WithArgs(wsID).
 		WillReturnError(sql.ErrConnDone)
@@ -2275,7 +2268,7 @@ func TestProxyA2A_PollMode_FailsClosedToPush(t *testing.T) {
 		var resp map[string]interface{}
 		_ = json.Unmarshal(w.Body.Bytes(), &resp)
 		if resp["status"] == "queued" {
-			t.Errorf("generic DB error on delivery_mode lookup silently queued the request — must fail-open-to-push, got body: %s", w.Body.String())
+			t.Errorf("DB error on delivery_mode lookup silently queued the request — must fail-closed-to-push, got body: %s", w.Body.String())
 		}
 	}
 
@@ -2284,37 +2277,6 @@ func TestProxyA2A_PollMode_FailsClosedToPush(t *testing.T) {
 	}
 }
 
-// TestLookupDeliveryMode_ContextCanceled_FailsClosed is the internal#497
-// regression test for the SECONDARY defect. It pins the exact invariant
-// that hid the ce2db75f regression for 5 days: when the delivery_mode read
-// fails because the context was cancelled (precisely what happened in the
-// detached delegation goroutine running on a returned request context),
-// lookupDeliveryMode MUST return an error and MUST NOT silently return
-// "push". Returning push there is what skipped the poll-mode short-circuit
-// and silently dropped 100% of poll-mode peer deliveries.
-//
-// A pre-cancelled context makes QueryRowContext fail with
-// context.Canceled deterministically — no DB rows are mocked because the
-// query never reaches a result.
-func TestLookupDeliveryMode_ContextCanceled_FailsClosed(t *testing.T) {
-	mock := setupTestDB(t)
-	// The query fails on the cancelled ctx before matching; provide a
-	// permissive expectation so sqlmock doesn't complain about the attempt.
-	mock.ExpectQuery("SELECT delivery_mode FROM workspaces WHERE id").
-		WillReturnError(context.Canceled)
-
-	ctx, cancel := context.WithCancel(context.Background())
-	cancel() // simulate the HTTP handler having returned (request ctx dead)
-
-	mode, err := lookupDeliveryMode(ctx, "ws-poll-peer")
-	if err == nil {
-		t.Fatalf("internal#497 regression: lookupDeliveryMode swallowed a context error and returned mode=%q with nil err — this is the exact 5-day silent-misrouting vector", mode)
-	}
-	if mode == models.DeliveryModePush {
-		t.Errorf("internal#497 regression: context error must NOT default to push (got mode=%q)", mode)
-	}
-}
-
 // ==================== a2aClient ResponseHeaderTimeout config ====================
 
 func TestA2AClientResponseHeaderTimeout(t *testing.T) {

workspace-server/internal/handlers/delegation.go

@@ -162,32 +162,8 @@ func (h *DelegationHandler) Delegate(c *gin.Context) {
 		},
 	})
 
-	// Fire-and-forget: send A2A in a background goroutine.
-	//
-	// internal#497 — the goroutine MUST NOT inherit the HTTP request's
-	// cancellation. `ctx` here is c.Request.Context(); the handler returns
-	// 202 a few lines below, which cancels that context immediately. Before
-	// this fix (regression ce2db75f) executeDelegation ran on the
-	// request-scoped ctx, so every DB op + proxy call in the detached
-	// goroutine failed `context canceled` the instant the 202 was written.
-	// That silently broke 100% of A2A peer delegations fleet-wide since
-	// 2026-05-12 (poll-mode peers never got their a2a_receive inbox row;
-	// lookupDeliveryMode swallowed the ctx error and defaulted to push).
-	//
-	// context.WithoutCancel detaches cancellation/deadline while PRESERVING
-	// all context values (trace/correlation/tenant ids that proxyA2ARequest
-	// and the broadcaster read off ctx) — this is the established pattern in
-	// this package (a2a_proxy.go:850, a2a_proxy_helpers.go:525,
-	// registry.go:822). The 30-minute ceiling matches the prior internal
-	// budget executeDelegation used before ce2db75f and the proxy's own
-	// absolute agent-dispatch ceiling (a2a_proxy.go forwardCtx).
-	delegationCtx, cancelDelegation := context.WithTimeout(
-		context.WithoutCancel(ctx), 30*time.Minute,
-	)
-	go func() {
-		defer cancelDelegation()
-		h.executeDelegation(delegationCtx, sourceID, body.TargetID, delegationID, a2aBody)
-	}()
+	// Fire-and-forget: send A2A in background goroutine
+	go h.executeDelegation(ctx, sourceID, body.TargetID, delegationID, a2aBody)
 
 	// Broadcast event so canvas shows delegation in real-time
 	h.broadcaster.RecordAndBroadcast(ctx, string(events.EventDelegationSent), sourceID, map[string]interface{}{

workspace-server/internal/handlers/delegation_test.go

@@ -16,65 +16,6 @@ import (
 	"github.com/gin-gonic/gin"
 )
 
-// ---------- internal#497 regression: detached goroutine ctx must outlive the handler ----------
-
-// TestDelegate_DetachedContext_SurvivesRequestCancellation pins the
-// load-bearing invariant that regression ce2db75f violated: the context
-// handed to executeDelegation in the fire-and-forget goroutine must NOT be
-// cancelled when the HTTP handler returns 202 (which cancels
-// c.Request.Context()). Before the fix, executeDelegation ran on the
-// request-scoped ctx, so every DB op + proxy call failed `context
-// canceled` the instant the 202 was written — silently breaking 100% of
-// A2A peer delegations fleet-wide since 2026-05-12.
-//
-// This test asserts the exact ctx-derivation contract used by Delegate
-// (context.WithoutCancel(parent) + a timeout budget): the derived context
-// (a) stays alive after the parent is cancelled, and (b) still carries
-// parent values (trace/correlation/tenant ids the downstream proxy +
-// broadcaster read off ctx). It is intentionally DB-free and fast.
-func TestDelegate_DetachedContext_SurvivesRequestCancellation(t *testing.T) {
-	type ctxKey string
-	const traceKey ctxKey = "trace-id"
-
-	// Simulate c.Request.Context() carrying a correlation value.
-	parent, cancelParent := context.WithCancel(
-		context.WithValue(context.Background(), traceKey, "trace-abc-123"),
-	)
-
-	// Exact derivation Delegate uses for the detached goroutine.
-	delegationCtx, cancelDelegation := context.WithTimeout(
-		context.WithoutCancel(parent), 30*time.Minute,
-	)
-	defer cancelDelegation()
-
-	// The HTTP handler "returns 202" → request context is cancelled.
-	cancelParent()
-
-	if err := parent.Err(); err == nil {
-		t.Fatal("precondition: parent context should be cancelled after the handler returns")
-	}
-
-	// (a) Cancellation MUST NOT propagate to the detached context.
-	select {
-	case <-delegationCtx.Done():
-		t.Fatalf("regression: detached delegation ctx was cancelled by the handler returning (err=%v) — executeDelegation would fail every DB op with `context canceled`", delegationCtx.Err())
-	default:
-		// alive — correct
-	}
-
-	// (b) Parent values MUST still be readable (WithoutCancel preserves
-	// values; trace/correlation/tenant ids the proxy + broadcaster use).
-	if got, _ := delegationCtx.Value(traceKey).(string); got != "trace-abc-123" {
-		t.Errorf("detached ctx lost the parent trace value: got %q, want %q", got, "trace-abc-123")
-	}
-
-	// And it still has a real deadline (the 30m budget), so it is not an
-	// unbounded background context.
-	if _, hasDeadline := delegationCtx.Deadline(); !hasDeadline {
-		t.Error("detached ctx must carry the 30-minute timeout budget, but has no deadline")
-	}
-}
-
 // ---------- Delegate: missing target_id → 400 ----------
 
 func TestDelegate_MissingTargetID(t *testing.T) {

workspace-server/internal/handlers/plugins_listing_test.go

@@ -1,141 +0,0 @@
-package handlers
-
-import (
-	"encoding/json"
-	"net/http"
-	"net/http/httptest"
-	"os"
-	"path/filepath"
-	"testing"
-
-	"github.com/gin-gonic/gin"
-)
-
-func TestListRegistry_EmptyDir(t *testing.T) {
-	dir := t.TempDir()
-	h := NewPluginsHandler(dir, nil, nil)
-
-	got := h.listRegistryFiltered("")
-	if len(got) != 0 {
-		t.Errorf("expected empty list, got %d plugins", len(got))
-	}
-}
-
-func TestListRegistry_IgnoresFiles(t *testing.T) {
-	dir := t.TempDir()
-	if err := os.WriteFile(filepath.Join(dir, "not-a-plugin.txt"), []byte("x"), 0600); err != nil {
-		t.Fatal(err)
-	}
-	h := NewPluginsHandler(dir, nil, nil)
-
-	got := h.listRegistryFiltered("")
-	if len(got) != 0 {
-		t.Errorf("expected empty list (files ignored), got %d", len(got))
-	}
-}
-
-func TestListRegistry_SinglePlugin(t *testing.T) {
-	dir := t.TempDir()
-	pluginDir := filepath.Join(dir, "my-plugin")
-	if err := os.Mkdir(pluginDir, 0755); err != nil {
-		t.Fatal(err)
-	}
-	if err := os.WriteFile(filepath.Join(pluginDir, "plugin.yaml"), []byte("name: my-plugin\nversion: 1.0.0\n"), 0600); err != nil {
-		t.Fatal(err)
-	}
-	h := NewPluginsHandler(dir, nil, nil)
-
-	got := h.listRegistryFiltered("")
-	if len(got) != 1 {
-		t.Fatalf("expected 1 plugin, got %d", len(got))
-	}
-	if got[0].Name != "my-plugin" {
-		t.Errorf("expected name 'my-plugin', got %q", got[0].Name)
-	}
-}
-
-func TestListRegistry_FiltersByRuntime(t *testing.T) {
-	dir := t.TempDir()
-	for _, spec := range []struct{ name, yaml string }{
-		{"runtime-a", "name: runtime-a\nruntimes:\n  - claude-code\n"},
-		{"runtime-b", "name: runtime-b\nruntimes:\n  - hermes\n"},
-		{"universal", "name: universal\nversion: 1.0.0\n"},
-	} {
-		pd := filepath.Join(dir, spec.name)
-		if err := os.Mkdir(pd, 0755); err != nil {
-			t.Fatal(err)
-		}
-		if err := os.WriteFile(filepath.Join(pd, "plugin.yaml"), []byte(spec.yaml), 0600); err != nil {
-			t.Fatal(err)
-		}
-	}
-	h := NewPluginsHandler(dir, nil, nil)
-
-	// Filter to claude-code: runtime-a matches, universal (no runtimes field)
-	// is always included per supportsRuntime semantics.
-	got := h.listRegistryFiltered("claude-code")
-	if len(got) != 2 {
-		t.Fatalf("expected 2 (runtime-a + universal), got %d: %v", len(got), func() []string {
-			ns := make([]string, len(got))
-			for i, p := range got { ns[i] = p.Name }
-			return ns
-		}())
-	}
-}
-
-func TestListRegistry_PluginWithNoRuntimeDeclarations_AlwaysIncluded(t *testing.T) {
-	dir := t.TempDir()
-	pd := filepath.Join(dir, "universal-plugin")
-	if err := os.Mkdir(pd, 0755); err != nil {
-		t.Fatal(err)
-	}
-	if err := os.WriteFile(filepath.Join(pd, "plugin.yaml"), []byte("name: universal-plugin\nversion: 1.0.0\n"), 0600); err != nil {
-		t.Fatal(err)
-	}
-	h := NewPluginsHandler(dir, nil, nil)
-
-	// When plugin declares no runtimes, it should always be included (try-it).
-	got := h.listRegistryFiltered("any-runtime")
-	if len(got) != 1 {
-		t.Errorf("expected 1 plugin (unspecified runtime), got %d", len(got))
-	}
-}
-
-func TestListRegistry_ReadDirError_ReturnsEmpty(t *testing.T) {
-	h := NewPluginsHandler("/nonexistent/path/for/plugins", nil, nil)
-	got := h.listRegistryFiltered("")
-	if len(got) != 0 {
-		t.Errorf("expected empty list on ReadDir error, got %d", len(got))
-	}
-}
-
-func TestListRegistry_HTTPEndpoint(t *testing.T) {
-	dir := t.TempDir()
-	pd := filepath.Join(dir, "test-plugin")
-	if err := os.Mkdir(pd, 0755); err != nil {
-		t.Fatal(err)
-	}
-	if err := os.WriteFile(filepath.Join(pd, "plugin.yaml"), []byte("name: test-plugin\nversion: 2.0.0\n"), 0600); err != nil {
-		t.Fatal(err)
-	}
-	h := NewPluginsHandler(dir, nil, nil)
-
-	w := httptest.NewRecorder()
-	c, _ := gin.CreateTestContext(w)
-	c.Request = httptest.NewRequest("GET", "/plugins", nil)
-	h.ListRegistry(c)
-
-	if w.Code != http.StatusOK {
-		t.Errorf("expected 200, got %d: %s", w.Code, w.Body.String())
-	}
-	var plugins []pluginInfo
-	if err := json.Unmarshal(w.Body.Bytes(), &plugins); err != nil {
-		t.Fatalf("failed to parse JSON: %v", err)
-	}
-	if len(plugins) != 1 {
-		t.Errorf("expected 1 plugin, got %d", len(plugins))
-	}
-	if plugins[0].Name != "test-plugin" {
-		t.Errorf("expected name 'test-plugin', got %q", plugins[0].Name)
-	}
-}