Fix stale abort result contaminating replacement turns after interrupt

When interrupting a Claude agent mid-tool-call and sending a replacement
message, the SDK's abort error result was being attributed to the new
foreground turn, causing [System Error] banners and displaced replies.

Root cause: pendingInterruptAbort was cleared by visible activity from
the new turn before the stale result arrived (timing race), and the
stale result then poisoned the replacement turn.

Fix:
- Suppress stale non-success results at the top of routeSdkMessageFromPump
  before any turn attribution, using both flag-based (pendingInterruptAbort)
  and content-based (isAbortError) detection
- Stop clearing pendingInterruptAbort on visible activity — only consume
  it when a result message arrives
- Prevent idle flash during replacement by checking pendingReplacement
  in agent-manager turn_completed/turn_canceled handlers
- Fix vitest env loading to use import.meta.url instead of process.cwd()
- Load .env.test eagerly in agent-configs.ts for collection-time availability

Includes regression tests covering the exact f160a2a3 daemon log ordering.

packages/server/src/server/agent/agent-manager.ts

@@ -2038,7 +2038,8 @@ export class AgentManager {
         agent.lastUsage = event.usage;
         agent.lastError = undefined;
         // For autonomous turns (not foreground), transition to idle
-        if (!isForegroundEvent && agent.lifecycle !== "idle") {
+        // unless a replacement is pending (avoid idle flash during replace)
+        if (!isForegroundEvent && agent.lifecycle !== "idle" && !agent.pendingReplacement) {
           (agent as ActiveManagedAgent).lifecycle = "idle";
           this.emitState(agent);
         }
@@ -2094,7 +2095,8 @@ export class AgentManager {
           "handleStreamEvent: turn_canceled",
         );
         // For autonomous turns, transition to idle
-        if (!isForegroundEvent) {
+        // unless a replacement is pending (avoid idle flash during replace)
+        if (!isForegroundEvent && !agent.pendingReplacement) {
           (agent as ActiveManagedAgent).lifecycle = "idle";
         }
         agent.lastError = undefined;