Method executeIdleCompaction

src/node/services/workspaceService.ts:9030–9112

* Execute idle compaction for a workspace directly from the backend. * * This path is frontend-independent: compaction still runs even if no UI is open. * Throws on failure so IdleCompactionService can log and continue with the next workspace.

(workspaceId: string)

   * Throws on failure so IdleCompactionService can log and continue with the next workspace.
   */
  async executeIdleCompaction(workspaceId: string): Promise<void> {
    assert(workspaceId.trim().length > 0, "executeIdleCompaction requires a non-empty workspaceId");

    const sendOptions = await this.buildIdleCompactionSendOptions(workspaceId);

    const muxMetadata: MuxMessageMetadata = {
      type: "compaction-request",
      rawCommand: "/compact",
      commandPrefix: "/compact",
      parsed: {
        model: sendOptions.model,
      },
      requestedModel: sendOptions.model,
      source: "idle-compaction",
      displayStatus: { emoji: "💤", message: "Compacting idle workspace..." },
    };

    const session = this.getOrCreateSession(workspaceId);
    if (session.isBusy()) {
      // Expected race (workspace became active), not a failure — do not report an outcome.
      throw new Error(`Failed to execute idle compaction: ${IDLE_ONLY_BUSY_SKIP_MESSAGE}`);
    }

    const sendResult = await this.sendMessage(
      workspaceId,
      buildCompactionMessageText({}),
      {
        ...sendOptions,
        muxMetadata,
      },
      {
        // Idle compaction runs in background; avoid mutating auto-resume counters.
        skipAutoResumeReset: true,
        // Backend-initiated maintenance turn: do not treat as explicit user re-engagement.
        synthetic: true,
        // If the workspace became active after eligibility checks, skip instead of queueing
        // stale maintenance work for later.
        requireIdle: true,
      }
    );

    if (!sendResult.success) {
      const rawError = sendResult.error;
      const formattedError =
        typeof rawError === "object" && rawError !== null
          ? "raw" in rawError && typeof rawError.raw === "string"
            ? rawError.raw
            : "message" in rawError && typeof rawError.message === "string"
              ? rawError.message
              : "type" in rawError && typeof rawError.type === "string"
                ? rawError.type
                : JSON.stringify(rawError)
          : String(rawError);
      // Report genuine pre-stream failures (e.g. invalid/unavailable compaction model) so the
      // idle loop can stop re-attempting this workspace. Mid-stream failures are reported
      // separately from the stream error/completion listeners. The requireIdle busy-skip is an
      // expected race (workspace became active), so it must NOT count toward suppression.
      const isBusySkip =