diff --git a/src/telegram/lane-delivery-state.ts b/src/telegram/lane-delivery-state.ts
new file mode 100644
index 00000000000..1761234ecaa
--- /dev/null
+++ b/src/telegram/lane-delivery-state.ts
@@ -0,0 +1,32 @@
+export type LaneDeliverySnapshot = {
+  delivered: boolean;
+  skippedNonSilent: number;
+  failedNonSilent: number;
+};
+
+export type LaneDeliveryStateTracker = {
+  markDelivered: () => void;
+  markNonSilentSkip: () => void;
+  markNonSilentFailure: () => void;
+  snapshot: () => LaneDeliverySnapshot;
+};
+
+export function createLaneDeliveryStateTracker(): LaneDeliveryStateTracker {
+  const state: LaneDeliverySnapshot = {
+    delivered: false,
+    skippedNonSilent: 0,
+    failedNonSilent: 0,
+  };
+  return {
+    markDelivered: () => {
+      state.delivered = true;
+    },
+    markNonSilentSkip: () => {
+      state.skippedNonSilent += 1;
+    },
+    markNonSilentFailure: () => {
+      state.failedNonSilent += 1;
+    },
+    snapshot: () => ({ ...state }),
+  };
+}
diff --git a/src/telegram/lane-delivery-text-deliverer.ts b/src/telegram/lane-delivery-text-deliverer.ts
new file mode 100644
index 00000000000..f244d086657
--- /dev/null
+++ b/src/telegram/lane-delivery-text-deliverer.ts
@@ -0,0 +1,463 @@
+import type { ReplyPayload } from "../auto-reply/types.js";
+import type { TelegramInlineButtons } from "./button-types.js";
+import type { TelegramDraftStream } from "./draft-stream.js";
+
+const MESSAGE_NOT_MODIFIED_RE =
+  /400:\s*Bad Request:\s*message is not modified|MESSAGE_NOT_MODIFIED/i;
+
+function isMessageNotModifiedError(err: unknown): boolean {
+  const text =
+    typeof err === "string"
+      ? err
+      : err instanceof Error
+        ? err.message
+        : typeof err === "object" && err && "description" in err
+          ? typeof err.description === "string"
+            ? err.description
+            : ""
+          : "";
+  return MESSAGE_NOT_MODIFIED_RE.test(text);
+}
+
+export type LaneName = "answer" | "reasoning";
+
+export type DraftLaneState = {
+  stream: TelegramDraftStream | undefined;
+  lastPartialText: string;
+  hasStreamedMessage: boolean;
+};
+
+export type ArchivedPreview = {
+  messageId: number;
+  textSnapshot: string;
+  // Boundary-finalized previews should remain visible even if no matching
+  // final edit arrives; superseded previews can be safely deleted.
+  deleteIfUnused?: boolean;
+};
+
+export type LaneDeliveryResult = "preview-finalized" | "preview-updated" | "sent" | "skipped";
+
+type CreateLaneTextDelivererParams = {
+  lanes: Record<LaneName, DraftLaneState>;
+  archivedAnswerPreviews: ArchivedPreview[];
+  finalizedPreviewByLane: Record<LaneName, boolean>;
+  draftMaxChars: number;
+  applyTextToPayload: (payload: ReplyPayload, text: string) => ReplyPayload;
+  sendPayload: (payload: ReplyPayload) => Promise<boolean>;
+  flushDraftLane: (lane: DraftLaneState) => Promise<void>;
+  stopDraftLane: (lane: DraftLaneState) => Promise<void>;
+  editPreview: (params: {
+    laneName: LaneName;
+    messageId: number;
+    text: string;
+    context: "final" | "update";
+    previewButtons?: TelegramInlineButtons;
+  }) => Promise<void>;
+  deletePreviewMessage: (messageId: number) => Promise<void>;
+  log: (message: string) => void;
+  markDelivered: () => void;
+};
+
+type DeliverLaneTextParams = {
+  laneName: LaneName;
+  text: string;
+  payload: ReplyPayload;
+  infoKind: string;
+  previewButtons?: TelegramInlineButtons;
+  allowPreviewUpdateForNonFinal?: boolean;
+};
+
+type TryUpdatePreviewParams = {
+  lane: DraftLaneState;
+  laneName: LaneName;
+  text: string;
+  previewButtons?: TelegramInlineButtons;
+  stopBeforeEdit?: boolean;
+  updateLaneSnapshot?: boolean;
+  skipRegressive: "always" | "existingOnly";
+  context: "final" | "update";
+  previewMessageId?: number;
+  previewTextSnapshot?: string;
+};
+
+type ConsumeArchivedAnswerPreviewParams = {
+  lane: DraftLaneState;
+  text: string;
+  payload: ReplyPayload;
+  previewButtons?: TelegramInlineButtons;
+  canEditViaPreview: boolean;
+};
+
+type PreviewUpdateContext = "final" | "update";
+type RegressiveSkipMode = "always" | "existingOnly";
+
+type ResolvePreviewTargetParams = {
+  lane: DraftLaneState;
+  previewMessageIdOverride?: number;
+  stopBeforeEdit: boolean;
+  context: PreviewUpdateContext;
+};
+
+type PreviewTargetResolution = {
+  hadPreviewMessage: boolean;
+  previewMessageId: number | undefined;
+  stopCreatesFirstPreview: boolean;
+};
+
+function shouldSkipRegressivePreviewUpdate(args: {
+  currentPreviewText: string | undefined;
+  text: string;
+  skipRegressive: RegressiveSkipMode;
+  hadPreviewMessage: boolean;
+}): boolean {
+  const currentPreviewText = args.currentPreviewText;
+  if (currentPreviewText === undefined) {
+    return false;
+  }
+  return (
+    currentPreviewText.startsWith(args.text) &&
+    args.text.length < currentPreviewText.length &&
+    (args.skipRegressive === "always" || args.hadPreviewMessage)
+  );
+}
+
+function resolvePreviewTarget(params: ResolvePreviewTargetParams): PreviewTargetResolution {
+  const lanePreviewMessageId = params.lane.stream?.messageId();
+  const previewMessageId =
+    typeof params.previewMessageIdOverride === "number"
+      ? params.previewMessageIdOverride
+      : lanePreviewMessageId;
+  const hadPreviewMessage =
+    typeof params.previewMessageIdOverride === "number" || typeof lanePreviewMessageId === "number";
+  return {
+    hadPreviewMessage,
+    previewMessageId: typeof previewMessageId === "number" ? previewMessageId : undefined,
+    stopCreatesFirstPreview:
+      params.stopBeforeEdit && !hadPreviewMessage && params.context === "final",
+  };
+}
+
+export function createLaneTextDeliverer(params: CreateLaneTextDelivererParams) {
+  const getLanePreviewText = (lane: DraftLaneState) => lane.lastPartialText;
+  const isDraftPreviewLane = (lane: DraftLaneState) => lane.stream?.previewMode?.() === "draft";
+  const canMaterializeDraftFinal = (
+    lane: DraftLaneState,
+    previewButtons?: TelegramInlineButtons,
+  ) => {
+    const hasPreviewButtons = Boolean(previewButtons && previewButtons.length > 0);
+    return (
+      isDraftPreviewLane(lane) &&
+      !hasPreviewButtons &&
+      typeof lane.stream?.materialize === "function"
+    );
+  };
+
+  const tryMaterializeDraftPreviewForFinal = async (args: {
+    lane: DraftLaneState;
+    laneName: LaneName;
+    text: string;
+  }): Promise<boolean> => {
+    const stream = args.lane.stream;
+    if (!stream || !isDraftPreviewLane(args.lane)) {
+      return false;
+    }
+    // Draft previews have no message_id to edit; materialize the final text
+    // into a real message and treat that as the finalized delivery.
+    stream.update(args.text);
+    const materializedMessageId = await stream.materialize?.();
+    if (typeof materializedMessageId !== "number") {
+      params.log(
+        `telegram: ${args.laneName} draft preview materialize produced no message id; falling back to standard send`,
+      );
+      return false;
+    }
+    args.lane.lastPartialText = args.text;
+    params.markDelivered();
+    return true;
+  };
+
+  const tryEditPreviewMessage = async (args: {
+    laneName: LaneName;
+    messageId: number;
+    text: string;
+    context: "final" | "update";
+    previewButtons?: TelegramInlineButtons;
+    updateLaneSnapshot: boolean;
+    lane: DraftLaneState;
+    treatEditFailureAsDelivered: boolean;
+  }): Promise<boolean> => {
+    try {
+      await params.editPreview({
+        laneName: args.laneName,
+        messageId: args.messageId,
+        text: args.text,
+        previewButtons: args.previewButtons,
+        context: args.context,
+      });
+      if (args.updateLaneSnapshot) {
+        args.lane.lastPartialText = args.text;
+      }
+      params.markDelivered();
+      return true;
+    } catch (err) {
+      if (isMessageNotModifiedError(err)) {
+        params.log(
+          `telegram: ${args.laneName} preview ${args.context} edit returned "message is not modified"; treating as delivered`,
+        );
+        params.markDelivered();
+        return true;
+      }
+      if (args.treatEditFailureAsDelivered) {
+        params.log(
+          `telegram: ${args.laneName} preview ${args.context} edit failed after stop-created flush; treating as delivered (${String(err)})`,
+        );
+        params.markDelivered();
+        return true;
+      }
+      params.log(
+        `telegram: ${args.laneName} preview ${args.context} edit failed; falling back to standard send (${String(err)})`,
+      );
+      return false;
+    }
+  };
+
+  const tryUpdatePreviewForLane = async ({
+    lane,
+    laneName,
+    text,
+    previewButtons,
+    stopBeforeEdit = false,
+    updateLaneSnapshot = false,
+    skipRegressive,
+    context,
+    previewMessageId: previewMessageIdOverride,
+    previewTextSnapshot,
+  }: TryUpdatePreviewParams): Promise<boolean> => {
+    const editPreview = (messageId: number, treatEditFailureAsDelivered: boolean) =>
+      tryEditPreviewMessage({
+        laneName,
+        messageId,
+        text,
+        context,
+        previewButtons,
+        updateLaneSnapshot,
+        lane,
+        treatEditFailureAsDelivered,
+      });
+    const finalizePreview = (
+      previewMessageId: number,
+      treatEditFailureAsDelivered: boolean,
+      hadPreviewMessage: boolean,
+    ): boolean | Promise<boolean> => {
+      const currentPreviewText = previewTextSnapshot ?? getLanePreviewText(lane);
+      const shouldSkipRegressive = shouldSkipRegressivePreviewUpdate({
+        currentPreviewText,
+        text,
+        skipRegressive,
+        hadPreviewMessage,
+      });
+      if (shouldSkipRegressive) {
+        params.markDelivered();
+        return true;
+      }
+      return editPreview(previewMessageId, treatEditFailureAsDelivered);
+    };
+    if (!lane.stream) {
+      return false;
+    }
+    const previewTargetBeforeStop = resolvePreviewTarget({
+      lane,
+      previewMessageIdOverride,
+      stopBeforeEdit,
+      context,
+    });
+    if (previewTargetBeforeStop.stopCreatesFirstPreview) {
+      // Final stop() can create the first visible preview message.
+      // Prime pending text so the stop flush sends the final text snapshot.
+      lane.stream.update(text);
+      await params.stopDraftLane(lane);
+      const previewTargetAfterStop = resolvePreviewTarget({
+        lane,
+        stopBeforeEdit: false,
+        context,
+      });
+      if (typeof previewTargetAfterStop.previewMessageId !== "number") {
+        return false;
+      }
+      return finalizePreview(previewTargetAfterStop.previewMessageId, true, false);
+    }
+    if (stopBeforeEdit) {
+      await params.stopDraftLane(lane);
+    }
+    const previewTargetAfterStop = resolvePreviewTarget({
+      lane,
+      previewMessageIdOverride,
+      stopBeforeEdit: false,
+      context,
+    });
+    if (typeof previewTargetAfterStop.previewMessageId !== "number") {
+      return false;
+    }
+    return finalizePreview(
+      previewTargetAfterStop.previewMessageId,
+      false,
+      previewTargetAfterStop.hadPreviewMessage,
+    );
+  };
+
+  const consumeArchivedAnswerPreviewForFinal = async ({
+    lane,
+    text,
+    payload,
+    previewButtons,
+    canEditViaPreview,
+  }: ConsumeArchivedAnswerPreviewParams): Promise<LaneDeliveryResult | undefined> => {
+    const archivedPreview = params.archivedAnswerPreviews.shift();
+    if (!archivedPreview) {
+      return undefined;
+    }
+    if (canEditViaPreview) {
+      const finalized = await tryUpdatePreviewForLane({
+        lane,
+        laneName: "answer",
+        text,
+        previewButtons,
+        stopBeforeEdit: false,
+        skipRegressive: "existingOnly",
+        context: "final",
+        previewMessageId: archivedPreview.messageId,
+        previewTextSnapshot: archivedPreview.textSnapshot,
+      });
+      if (finalized) {
+        return "preview-finalized";
+      }
+    }
+    // Send the replacement message first, then clean up the old preview.
+    // This avoids the visual "disappear then reappear" flash.
+    const delivered = await params.sendPayload(params.applyTextToPayload(payload, text));
+    // Once this archived preview is consumed by a fallback final send, delete it
+    // regardless of deleteIfUnused. That flag only applies to unconsumed boundaries.
+    if (delivered || archivedPreview.deleteIfUnused !== false) {
+      try {
+        await params.deletePreviewMessage(archivedPreview.messageId);
+      } catch (err) {
+        params.log(
+          `telegram: archived answer preview cleanup failed (${archivedPreview.messageId}): ${String(err)}`,
+        );
+      }
+    }
+    return delivered ? "sent" : "skipped";
+  };
+
+  return async ({
+    laneName,
+    text,
+    payload,
+    infoKind,
+    previewButtons,
+    allowPreviewUpdateForNonFinal = false,
+  }: DeliverLaneTextParams): Promise<LaneDeliveryResult> => {
+    const lane = params.lanes[laneName];
+    const hasMedia = Boolean(payload.mediaUrl) || (payload.mediaUrls?.length ?? 0) > 0;
+    const canEditViaPreview =
+      !hasMedia && text.length > 0 && text.length <= params.draftMaxChars && !payload.isError;
+
+    if (infoKind === "final") {
+      if (laneName === "answer") {
+        const archivedResult = await consumeArchivedAnswerPreviewForFinal({
+          lane,
+          text,
+          payload,
+          previewButtons,
+          canEditViaPreview,
+        });
+        if (archivedResult) {
+          return archivedResult;
+        }
+      }
+      if (canEditViaPreview && !params.finalizedPreviewByLane[laneName]) {
+        await params.flushDraftLane(lane);
+        if (laneName === "answer") {
+          const archivedResultAfterFlush = await consumeArchivedAnswerPreviewForFinal({
+            lane,
+            text,
+            payload,
+            previewButtons,
+            canEditViaPreview,
+          });
+          if (archivedResultAfterFlush) {
+            return archivedResultAfterFlush;
+          }
+        }
+        if (canMaterializeDraftFinal(lane, previewButtons)) {
+          const materialized = await tryMaterializeDraftPreviewForFinal({
+            lane,
+            laneName,
+            text,
+          });
+          if (materialized) {
+            params.finalizedPreviewByLane[laneName] = true;
+            return "preview-finalized";
+          }
+        }
+        const finalized = await tryUpdatePreviewForLane({
+          lane,
+          laneName,
+          text,
+          previewButtons,
+          stopBeforeEdit: true,
+          skipRegressive: "existingOnly",
+          context: "final",
+        });
+        if (finalized) {
+          params.finalizedPreviewByLane[laneName] = true;
+          return "preview-finalized";
+        }
+      } else if (!hasMedia && !payload.isError && text.length > params.draftMaxChars) {
+        params.log(
+          `telegram: preview final too long for edit (${text.length} > ${params.draftMaxChars}); falling back to standard send`,
+        );
+      }
+      await params.stopDraftLane(lane);
+      const delivered = await params.sendPayload(params.applyTextToPayload(payload, text));
+      return delivered ? "sent" : "skipped";
+    }
+
+    if (allowPreviewUpdateForNonFinal && canEditViaPreview) {
+      if (isDraftPreviewLane(lane)) {
+        // DM draft flow has no message_id to edit; updates are sent via sendMessageDraft.
+        // Only mark as updated when the draft flush actually emits an update.
+        const previewRevisionBeforeFlush = lane.stream?.previewRevision?.() ?? 0;
+        lane.stream?.update(text);
+        await params.flushDraftLane(lane);
+        const previewUpdated = (lane.stream?.previewRevision?.() ?? 0) > previewRevisionBeforeFlush;
+        if (!previewUpdated) {
+          params.log(
+            `telegram: ${laneName} draft preview update not emitted; falling back to standard send`,
+          );
+          const delivered = await params.sendPayload(params.applyTextToPayload(payload, text));
+          return delivered ? "sent" : "skipped";
+        }
+        lane.lastPartialText = text;
+        params.markDelivered();
+        return "preview-updated";
+      }
+      const updated = await tryUpdatePreviewForLane({
+        lane,
+        laneName,
+        text,
+        previewButtons,
+        stopBeforeEdit: false,
+        updateLaneSnapshot: true,
+        skipRegressive: "always",
+        context: "update",
+      });
+      if (updated) {
+        return "preview-updated";
+      }
+    }
+
+    const delivered = await params.sendPayload(params.applyTextToPayload(payload, text));
+    return delivered ? "sent" : "skipped";
+  };
+}
diff --git a/src/telegram/lane-delivery.ts b/src/telegram/lane-delivery.ts
index d46fd66cf57..213b05e1158 100644
--- a/src/telegram/lane-delivery.ts
+++ b/src/telegram/lane-delivery.ts
@@ -1,496 +1,12 @@
-import type { ReplyPayload } from "../auto-reply/types.js";
-import type { TelegramInlineButtons } from "./button-types.js";
-import type { TelegramDraftStream } from "./draft-stream.js";
-
-const MESSAGE_NOT_MODIFIED_RE =
-  /400:\s*Bad Request:\s*message is not modified|MESSAGE_NOT_MODIFIED/i;
-
-function isMessageNotModifiedError(err: unknown): boolean {
-  const text =
-    typeof err === "string"
-      ? err
-      : err instanceof Error
-        ? err.message
-        : typeof err === "object" && err && "description" in err
-          ? typeof err.description === "string"
-            ? err.description
-            : ""
-          : "";
-  return MESSAGE_NOT_MODIFIED_RE.test(text);
-}
-
-export type LaneName = "answer" | "reasoning";
-
-export type DraftLaneState = {
-  stream: TelegramDraftStream | undefined;
-  lastPartialText: string;
-  hasStreamedMessage: boolean;
-};
-
-export type ArchivedPreview = {
-  messageId: number;
-  textSnapshot: string;
-  // Boundary-finalized previews should remain visible even if no matching
-  // final edit arrives; superseded previews can be safely deleted.
-  deleteIfUnused?: boolean;
-};
-
-export type LaneDeliveryResult = "preview-finalized" | "preview-updated" | "sent" | "skipped";
-
-export type LaneDeliverySnapshot = {
-  delivered: boolean;
-  skippedNonSilent: number;
-  failedNonSilent: number;
-};
-
-export type LaneDeliveryStateTracker = {
-  markDelivered: () => void;
-  markNonSilentSkip: () => void;
-  markNonSilentFailure: () => void;
-  snapshot: () => LaneDeliverySnapshot;
-};
-
-export function createLaneDeliveryStateTracker(): LaneDeliveryStateTracker {
-  const state: LaneDeliverySnapshot = {
-    delivered: false,
-    skippedNonSilent: 0,
-    failedNonSilent: 0,
-  };
-  return {
-    markDelivered: () => {
-      state.delivered = true;
-    },
-    markNonSilentSkip: () => {
-      state.skippedNonSilent += 1;
-    },
-    markNonSilentFailure: () => {
-      state.failedNonSilent += 1;
-    },
-    snapshot: () => ({ ...state }),
-  };
-}
-
-type CreateLaneTextDelivererParams = {
-  lanes: Record<LaneName, DraftLaneState>;
-  archivedAnswerPreviews: ArchivedPreview[];
-  finalizedPreviewByLane: Record<LaneName, boolean>;
-  draftMaxChars: number;
-  applyTextToPayload: (payload: ReplyPayload, text: string) => ReplyPayload;
-  sendPayload: (payload: ReplyPayload) => Promise<boolean>;
-  flushDraftLane: (lane: DraftLaneState) => Promise<void>;
-  stopDraftLane: (lane: DraftLaneState) => Promise<void>;
-  editPreview: (params: {
-    laneName: LaneName;
-    messageId: number;
-    text: string;
-    context: "final" | "update";
-    previewButtons?: TelegramInlineButtons;
-  }) => Promise<void>;
-  deletePreviewMessage: (messageId: number) => Promise<void>;
-  log: (message: string) => void;
-  markDelivered: () => void;
-};
-
-type DeliverLaneTextParams = {
-  laneName: LaneName;
-  text: string;
-  payload: ReplyPayload;
-  infoKind: string;
-  previewButtons?: TelegramInlineButtons;
-  allowPreviewUpdateForNonFinal?: boolean;
-};
-
-type TryUpdatePreviewParams = {
-  lane: DraftLaneState;
-  laneName: LaneName;
-  text: string;
-  previewButtons?: TelegramInlineButtons;
-  stopBeforeEdit?: boolean;
-  updateLaneSnapshot?: boolean;
-  skipRegressive: "always" | "existingOnly";
-  context: "final" | "update";
-  previewMessageId?: number;
-  previewTextSnapshot?: string;
-};
-
-type ConsumeArchivedAnswerPreviewParams = {
-  lane: DraftLaneState;
-  text: string;
-  payload: ReplyPayload;
-  previewButtons?: TelegramInlineButtons;
-  canEditViaPreview: boolean;
-};
-
-type PreviewUpdateContext = "final" | "update";
-type RegressiveSkipMode = "always" | "existingOnly";
-
-type ResolvePreviewTargetParams = {
-  lane: DraftLaneState;
-  previewMessageIdOverride?: number;
-  stopBeforeEdit: boolean;
-  context: PreviewUpdateContext;
-};
-
-type PreviewTargetResolution = {
-  hadPreviewMessage: boolean;
-  previewMessageId: number | undefined;
-  stopCreatesFirstPreview: boolean;
-};
-
-function shouldSkipRegressivePreviewUpdate(args: {
-  currentPreviewText: string | undefined;
-  text: string;
-  skipRegressive: RegressiveSkipMode;
-  hadPreviewMessage: boolean;
-}): boolean {
-  const currentPreviewText = args.currentPreviewText;
-  if (currentPreviewText === undefined) {
-    return false;
-  }
-  return (
-    currentPreviewText.startsWith(args.text) &&
-    args.text.length < currentPreviewText.length &&
-    (args.skipRegressive === "always" || args.hadPreviewMessage)
-  );
-}
-
-function resolvePreviewTarget(params: ResolvePreviewTargetParams): PreviewTargetResolution {
-  const lanePreviewMessageId = params.lane.stream?.messageId();
-  const previewMessageId =
-    typeof params.previewMessageIdOverride === "number"
-      ? params.previewMessageIdOverride
-      : lanePreviewMessageId;
-  const hadPreviewMessage =
-    typeof params.previewMessageIdOverride === "number" || typeof lanePreviewMessageId === "number";
-  return {
-    hadPreviewMessage,
-    previewMessageId: typeof previewMessageId === "number" ? previewMessageId : undefined,
-    stopCreatesFirstPreview:
-      params.stopBeforeEdit && !hadPreviewMessage && params.context === "final",
-  };
-}
-
-export function createLaneTextDeliverer(params: CreateLaneTextDelivererParams) {
-  const getLanePreviewText = (lane: DraftLaneState) => lane.lastPartialText;
-  const isDraftPreviewLane = (lane: DraftLaneState) => lane.stream?.previewMode?.() === "draft";
-  const canMaterializeDraftFinal = (
-    lane: DraftLaneState,
-    previewButtons?: TelegramInlineButtons,
-  ) => {
-    const hasPreviewButtons = Boolean(previewButtons && previewButtons.length > 0);
-    return (
-      isDraftPreviewLane(lane) &&
-      !hasPreviewButtons &&
-      typeof lane.stream?.materialize === "function"
-    );
-  };
-
-  const tryMaterializeDraftPreviewForFinal = async (args: {
-    lane: DraftLaneState;
-    laneName: LaneName;
-    text: string;
-  }): Promise<boolean> => {
-    const stream = args.lane.stream;
-    if (!stream || !isDraftPreviewLane(args.lane)) {
-      return false;
-    }
-    // Draft previews have no message_id to edit; materialize the final text
-    // into a real message and treat that as the finalized delivery.
-    stream.update(args.text);
-    const materializedMessageId = await stream.materialize?.();
-    if (typeof materializedMessageId !== "number") {
-      params.log(
-        `telegram: ${args.laneName} draft preview materialize produced no message id; falling back to standard send`,
-      );
-      return false;
-    }
-    args.lane.lastPartialText = args.text;
-    params.markDelivered();
-    return true;
-  };
-
-  const tryEditPreviewMessage = async (args: {
-    laneName: LaneName;
-    messageId: number;
-    text: string;
-    context: "final" | "update";
-    previewButtons?: TelegramInlineButtons;
-    updateLaneSnapshot: boolean;
-    lane: DraftLaneState;
-    treatEditFailureAsDelivered: boolean;
-  }): Promise<boolean> => {
-    try {
-      await params.editPreview({
-        laneName: args.laneName,
-        messageId: args.messageId,
-        text: args.text,
-        previewButtons: args.previewButtons,
-        context: args.context,
-      });
-      if (args.updateLaneSnapshot) {
-        args.lane.lastPartialText = args.text;
-      }
-      params.markDelivered();
-      return true;
-    } catch (err) {
-      if (isMessageNotModifiedError(err)) {
-        params.log(
-          `telegram: ${args.laneName} preview ${args.context} edit returned "message is not modified"; treating as delivered`,
-        );
-        params.markDelivered();
-        return true;
-      }
-      if (args.treatEditFailureAsDelivered) {
-        params.log(
-          `telegram: ${args.laneName} preview ${args.context} edit failed after stop-created flush; treating as delivered (${String(err)})`,
-        );
-        params.markDelivered();
-        return true;
-      }
-      params.log(
-        `telegram: ${args.laneName} preview ${args.context} edit failed; falling back to standard send (${String(err)})`,
-      );
-      return false;
-    }
-  };
-
-  const tryUpdatePreviewForLane = async ({
-    lane,
-    laneName,
-    text,
-    previewButtons,
-    stopBeforeEdit = false,
-    updateLaneSnapshot = false,
-    skipRegressive,
-    context,
-    previewMessageId: previewMessageIdOverride,
-    previewTextSnapshot,
-  }: TryUpdatePreviewParams): Promise<boolean> => {
-    const editPreview = (messageId: number, treatEditFailureAsDelivered: boolean) =>
-      tryEditPreviewMessage({
-        laneName,
-        messageId,
-        text,
-        context,
-        previewButtons,
-        updateLaneSnapshot,
-        lane,
-        treatEditFailureAsDelivered,
-      });
-    const finalizePreview = (
-      previewMessageId: number,
-      treatEditFailureAsDelivered: boolean,
-      hadPreviewMessage: boolean,
-    ): boolean | Promise<boolean> => {
-      const currentPreviewText = previewTextSnapshot ?? getLanePreviewText(lane);
-      const shouldSkipRegressive = shouldSkipRegressivePreviewUpdate({
-        currentPreviewText,
-        text,
-        skipRegressive,
-        hadPreviewMessage,
-      });
-      if (shouldSkipRegressive) {
-        params.markDelivered();
-        return true;
-      }
-      return editPreview(previewMessageId, treatEditFailureAsDelivered);
-    };
-    if (!lane.stream) {
-      return false;
-    }
-    const previewTargetBeforeStop = resolvePreviewTarget({
-      lane,
-      previewMessageIdOverride,
-      stopBeforeEdit,
-      context,
-    });
-    if (previewTargetBeforeStop.stopCreatesFirstPreview) {
-      // Final stop() can create the first visible preview message.
-      // Prime pending text so the stop flush sends the final text snapshot.
-      lane.stream.update(text);
-      await params.stopDraftLane(lane);
-      const previewTargetAfterStop = resolvePreviewTarget({
-        lane,
-        stopBeforeEdit: false,
-        context,
-      });
-      if (typeof previewTargetAfterStop.previewMessageId !== "number") {
-        return false;
-      }
-      return finalizePreview(previewTargetAfterStop.previewMessageId, true, false);
-    }
-    if (stopBeforeEdit) {
-      await params.stopDraftLane(lane);
-    }
-    const previewTargetAfterStop = resolvePreviewTarget({
-      lane,
-      previewMessageIdOverride,
-      stopBeforeEdit: false,
-      context,
-    });
-    if (typeof previewTargetAfterStop.previewMessageId !== "number") {
-      return false;
-    }
-    return finalizePreview(
-      previewTargetAfterStop.previewMessageId,
-      false,
-      previewTargetAfterStop.hadPreviewMessage,
-    );
-  };
-
-  const consumeArchivedAnswerPreviewForFinal = async ({
-    lane,
-    text,
-    payload,
-    previewButtons,
-    canEditViaPreview,
-  }: ConsumeArchivedAnswerPreviewParams): Promise<LaneDeliveryResult | undefined> => {
-    const archivedPreview = params.archivedAnswerPreviews.shift();
-    if (!archivedPreview) {
-      return undefined;
-    }
-    if (canEditViaPreview) {
-      const finalized = await tryUpdatePreviewForLane({
-        lane,
-        laneName: "answer",
-        text,
-        previewButtons,
-        stopBeforeEdit: false,
-        skipRegressive: "existingOnly",
-        context: "final",
-        previewMessageId: archivedPreview.messageId,
-        previewTextSnapshot: archivedPreview.textSnapshot,
-      });
-      if (finalized) {
-        return "preview-finalized";
-      }
-    }
-    // Send the replacement message first, then clean up the old preview.
-    // This avoids the visual "disappear then reappear" flash.
-    const delivered = await params.sendPayload(params.applyTextToPayload(payload, text));
-    // Once this archived preview is consumed by a fallback final send, delete it
-    // regardless of deleteIfUnused. That flag only applies to unconsumed boundaries.
-    if (delivered || archivedPreview.deleteIfUnused !== false) {
-      try {
-        await params.deletePreviewMessage(archivedPreview.messageId);
-      } catch (err) {
-        params.log(
-          `telegram: archived answer preview cleanup failed (${archivedPreview.messageId}): ${String(err)}`,
-        );
-      }
-    }
-    return delivered ? "sent" : "skipped";
-  };
-
-  return async ({
-    laneName,
-    text,
-    payload,
-    infoKind,
-    previewButtons,
-    allowPreviewUpdateForNonFinal = false,
-  }: DeliverLaneTextParams): Promise<LaneDeliveryResult> => {
-    const lane = params.lanes[laneName];
-    const hasMedia = Boolean(payload.mediaUrl) || (payload.mediaUrls?.length ?? 0) > 0;
-    const canEditViaPreview =
-      !hasMedia && text.length > 0 && text.length <= params.draftMaxChars && !payload.isError;
-
-    if (infoKind === "final") {
-      if (laneName === "answer") {
-        const archivedResult = await consumeArchivedAnswerPreviewForFinal({
-          lane,
-          text,
-          payload,
-          previewButtons,
-          canEditViaPreview,
-        });
-        if (archivedResult) {
-          return archivedResult;
-        }
-      }
-      if (canEditViaPreview && !params.finalizedPreviewByLane[laneName]) {
-        await params.flushDraftLane(lane);
-        if (laneName === "answer") {
-          const archivedResultAfterFlush = await consumeArchivedAnswerPreviewForFinal({
-            lane,
-            text,
-            payload,
-            previewButtons,
-            canEditViaPreview,
-          });
-          if (archivedResultAfterFlush) {
-            return archivedResultAfterFlush;
-          }
-        }
-        if (canMaterializeDraftFinal(lane, previewButtons)) {
-          const materialized = await tryMaterializeDraftPreviewForFinal({
-            lane,
-            laneName,
-            text,
-          });
-          if (materialized) {
-            params.finalizedPreviewByLane[laneName] = true;
-            return "preview-finalized";
-          }
-        }
-        const finalized = await tryUpdatePreviewForLane({
-          lane,
-          laneName,
-          text,
-          previewButtons,
-          stopBeforeEdit: true,
-          skipRegressive: "existingOnly",
-          context: "final",
-        });
-        if (finalized) {
-          params.finalizedPreviewByLane[laneName] = true;
-          return "preview-finalized";
-        }
-      } else if (!hasMedia && !payload.isError && text.length > params.draftMaxChars) {
-        params.log(
-          `telegram: preview final too long for edit (${text.length} > ${params.draftMaxChars}); falling back to standard send`,
-        );
-      }
-      await params.stopDraftLane(lane);
-      const delivered = await params.sendPayload(params.applyTextToPayload(payload, text));
-      return delivered ? "sent" : "skipped";
-    }
-
-    if (allowPreviewUpdateForNonFinal && canEditViaPreview) {
-      if (isDraftPreviewLane(lane)) {
-        // DM draft flow has no message_id to edit; updates are sent via sendMessageDraft.
-        // Only mark as updated when the draft flush actually emits an update.
-        const previewRevisionBeforeFlush = lane.stream?.previewRevision?.() ?? 0;
-        lane.stream?.update(text);
-        await params.flushDraftLane(lane);
-        const previewUpdated = (lane.stream?.previewRevision?.() ?? 0) > previewRevisionBeforeFlush;
-        if (!previewUpdated) {
-          params.log(
-            `telegram: ${laneName} draft preview update not emitted; falling back to standard send`,
-          );
-          const delivered = await params.sendPayload(params.applyTextToPayload(payload, text));
-          return delivered ? "sent" : "skipped";
-        }
-        lane.lastPartialText = text;
-        params.markDelivered();
-        return "preview-updated";
-      }
-      const updated = await tryUpdatePreviewForLane({
-        lane,
-        laneName,
-        text,
-        previewButtons,
-        stopBeforeEdit: false,
-        updateLaneSnapshot: true,
-        skipRegressive: "always",
-        context: "update",
-      });
-      if (updated) {
-        return "preview-updated";
-      }
-    }
-
-    const delivered = await params.sendPayload(params.applyTextToPayload(payload, text));
-    return delivered ? "sent" : "skipped";
-  };
-}
+export {
+  type ArchivedPreview,
+  createLaneTextDeliverer,
+  type DraftLaneState,
+  type LaneDeliveryResult,
+  type LaneName,
+} from "./lane-delivery-text-deliverer.js";
+export {
+  createLaneDeliveryStateTracker,
+  type LaneDeliverySnapshot,
+  type LaneDeliveryStateTracker,
+} from "./lane-delivery-state.js";