diff --git a/packages/studio/src/player/components/timelineCollision.test.ts b/packages/studio/src/player/components/timelineCollision.test.ts
new file mode 100644
index 0000000000..c1c9b26ca5
--- /dev/null
+++ b/packages/studio/src/player/components/timelineCollision.test.ts
@@ -0,0 +1,437 @@
+import { describe, expect, it } from "vitest";
+import type { TimelineElement } from "../store/playerStore";
+import {
+  clampTrackToZone,
+  isInsertAllowedForZone,
+  isLaneFree,
+  resolveInsertRow,
+  resolvePlacement,
+  resolveZoneDropPlacement,
+  timeRangesOverlap,
+} from "./timelineCollision";
+
+function el(id: string, track: number, start: number, duration: number): TimelineElement {
+  return { id, tag: "video", start, duration, track };
+}
+
+describe("timeRangesOverlap", () => {
+  it("detects overlap and treats touching edges as free (half-open)", () => {
+    expect(timeRangesOverlap(0, 2, 1, 3)).toBe(true);
+    expect(timeRangesOverlap(0, 2, 2, 4)).toBe(false); // touching at 2
+    expect(timeRangesOverlap(2, 4, 0, 2)).toBe(false);
+  });
+});
+
+describe("isLaneFree", () => {
+  const els = [el("a", 0, 0, 5), el("b", 1, 2, 3)];
+
+  it("is free when nothing overlaps on the track", () => {
+    expect(isLaneFree(els, 2, 0, 5, null)).toBe(true);
+    expect(isLaneFree(els, 0, 6, 8, null)).toBe(true); // same track, no time overlap
+  });
+
+  it("is occupied when a clip overlaps on the same track", () => {
+    expect(isLaneFree(els, 0, 1, 3, null)).toBe(false);
+  });
+
+  it("ignores the excluded (dragged) clip", () => {
+    expect(isLaneFree(els, 0, 1, 3, "a")).toBe(true);
+  });
+});
+
+describe("resolvePlacement", () => {
+  const trackOrder = [0, 1, 2, 3];
+
+  it("keeps the desired lane when it is free", () => {
+    const els = [el("a", 2, 0, 4)];
+    expect(
+      resolvePlacement({
+        elements: els,
+        desiredTrack: 1,
+        start: 0,
+        duration: 4,
+        trackOrder,
+        excludeKey: null,
+      }),
+    ).toEqual({
+      track: 1,
+      needsInsert: false,
+    });
+  });
+
+  it("pushes up to the nearest free lane above when the target is occupied", () => {
+    // desired = 2 occupied; 1 free above → land on 1
+    const els = [el("blocker", 2, 0, 4)];
+    expect(
+      resolvePlacement({
+        elements: els,
+        desiredTrack: 2,
+        start: 1,
+        duration: 2,
+        trackOrder,
+        excludeKey: null,
+      }),
+    ).toEqual({ track: 1, needsInsert: false });
+  });
+
+  it("prefers up even when a lane below is also free", () => {
+    // desired 2 occupied; both 1 (up) and 3 (down) free → up wins
+    const els = [el("blocker", 2, 0, 5)];
+    expect(
+      resolvePlacement({
+        elements: els,
+        desiredTrack: 2,
+        start: 0,
+        duration: 3,
+        trackOrder,
+        excludeKey: null,
+      }),
+    ).toEqual({ track: 1, needsInsert: false });
+  });
+
+  it("falls to a lane below when every lane above is occupied", () => {
+    // desired 1 occupied; 0 occupied above; 2 free below → land on 2
+    const els = [el("x", 0, 0, 5), el("y", 1, 0, 5)];
+    expect(
+      resolvePlacement({
+        elements: els,
+        desiredTrack: 1,
+        start: 1,
+        duration: 2,
+        trackOrder,
+        excludeKey: null,
+      }),
+    ).toEqual({ track: 2, needsInsert: false });
+  });
+
+  it("signals needsInsert when no lane is free", () => {
+    const els = [el("a", 0, 0, 9), el("b", 1, 0, 9), el("c", 2, 0, 9), el("d", 3, 0, 9)];
+    expect(
+      resolvePlacement({
+        elements: els,
+        desiredTrack: 2,
+        start: 1,
+        duration: 2,
+        trackOrder,
+        excludeKey: null,
+      }),
+    ).toEqual({ track: 2, needsInsert: true });
+  });
+
+  it("signals needsInsert when the desired track is occupied but absent from the zone's lanes (#2195)", () => {
+    // desiredTrack 5 is occupied yet not in trackOrder (its kind-zone has no lane
+    // here). Landing on it would overlap, so the empty-zone branch must insert —
+    // not silently land on the occupied track (the placement hole).
+    const els = [el("blocker", 5, 0, 5)];
+    expect(
+      resolvePlacement({
+        elements: els,
+        desiredTrack: 5,
+        start: 1,
+        duration: 2,
+        trackOrder: [],
+        excludeKey: null,
+      }),
+    ).toEqual({ track: 5, needsInsert: true });
+  });
+
+  it("signals needsInsert when the desired track is FREE but absent from the zone's lanes (#2195 free-span hole)", () => {
+    // desiredTrack 5 is FREE (no overlap) yet not in trackOrder — its kind-zone has
+    // no lane here. The old code short-circuited on isLaneFree and landed on the
+    // foreign-zone lane; the zone check must win and signal an insert.
+    const els = [el("elsewhere", 9, 0, 5)];
+    expect(
+      resolvePlacement({
+        elements: els,
+        desiredTrack: 5,
+        start: 1,
+        duration: 2,
+        trackOrder: [],
+        excludeKey: null,
+      }),
+    ).toEqual({ track: 5, needsInsert: true });
+  });
+
+  it("placeholder-scenario excludes the dragged clip so it does not collide with itself", () => {
+    const els = [el("self", 1, 0, 5)];
+    expect(
+      resolvePlacement({
+        elements: els,
+        desiredTrack: 1,
+        start: 0,
+        duration: 5,
+        trackOrder,
+        excludeKey: "self",
+      }),
+    ).toEqual({ track: 1, needsInsert: false });
+  });
+});
+
+describe("resolveInsertRow", () => {
+  const n = 3; // three lanes: rows 0,1,2
+
+  it("targets the lane (null) when over its middle band", () => {
+    expect(resolveInsertRow(1.5, n, 0.22)).toBe(null); // dead center of lane 1
+  });
+
+  it("inserts at the top boundary of a lane when near its top edge", () => {
+    expect(resolveInsertRow(1.1, n, 0.22)).toBe(1); // just into lane 1 → boundary above it
+  });
+
+  it("inserts at the bottom boundary of a lane when near its bottom edge", () => {
+    expect(resolveInsertRow(1.9, n, 0.22)).toBe(2); // near bottom of lane 1 → boundary below
+  });
+
+  it("inserts above the top lane when the pointer is above everything", () => {
+    expect(resolveInsertRow(-0.5, n, 0.22)).toBe(0);
+  });
+
+  it("inserts below the bottom lane when the pointer is past the last lane", () => {
+    expect(resolveInsertRow(3.4, n, 0.22)).toBe(3);
+  });
+});
+
+// (The production insert-band suite imports INSERT_BOUNDARY_BAND from timelineLayout,
+// which lands with the timeline glue swap — the full suite re-lands there.)
+describe("clampTrackToZone", () => {
+  // trackOrder [0,1,2,3]: rows 0,1 = visual; rows 2,3 = audio (audioRow = 2).
+  const order = [0, 1, 2, 3];
+
+  it("is a no-op when there is no audio zone", () => {
+    expect(clampTrackToZone(3, order, -1, false)).toBe(3);
+  });
+
+  it("keeps a visual clip in the visual zone", () => {
+    expect(clampTrackToZone(1, order, 2, false)).toBe(1); // already visual
+    expect(clampTrackToZone(3, order, 2, false)).toBe(1); // in audio → last visual lane
+  });
+
+  it("keeps an audio clip in the audio zone", () => {
+    expect(clampTrackToZone(2, order, 2, true)).toBe(2); // already audio
+    expect(clampTrackToZone(0, order, 2, true)).toBe(2); // in visual → first audio lane
+  });
+});
+
+describe("isInsertAllowedForZone", () => {
+  // audioRow = 2
+  it("allows any insert when there is no audio zone", () => {
+    expect(isInsertAllowedForZone(0, -1, false)).toBe(true);
+    expect(isInsertAllowedForZone(3, -1, true)).toBe(true);
+  });
+
+  it("allows a visual insert only at/above the audio zone top", () => {
+    expect(isInsertAllowedForZone(0, 2, false)).toBe(true);
+    expect(isInsertAllowedForZone(2, 2, false)).toBe(true); // bottom of the visual zone
+    expect(isInsertAllowedForZone(3, 2, false)).toBe(false); // inside the audio zone
+  });
+
+  it("allows an audio insert only at/below the audio zone top (audio clips make audio tracks)", () => {
+    expect(isInsertAllowedForZone(2, 2, true)).toBe(true);
+    expect(isInsertAllowedForZone(4, 2, true)).toBe(true); // below the bottom
+    expect(isInsertAllowedForZone(1, 2, true)).toBe(false); // inside the visual zone
+  });
+});
+
+describe("resolveZoneDropPlacement (the whole drop decision, no same-track overlap)", () => {
+  // order [0,1,2] visual + [3] audio. audioRow = 3.
+  const order = [0, 1, 2, 3];
+  const audioTracks = new Set([3]);
+  const base = {
+    order,
+    audioTracks,
+    deliberateInsertRow: null as number | null,
+    start: 2,
+    duration: 2,
+    dragKey: "x",
+    isAudio: false,
+  };
+
+  it("lands on the aimed track when it is free at that time", () => {
+    expect(
+      resolveZoneDropPlacement({ ...base, elements: [el("a", 1, 10, 3)], desiredTrack: 1 }),
+    ).toEqual({ track: 1, insertRow: null });
+  });
+
+  it("relocates UP to the nearest free track when the aimed spot overlaps a clip", () => {
+    expect(
+      resolveZoneDropPlacement({ ...base, elements: [el("a", 1, 0, 5)], desiredTrack: 1 }),
+    ).toEqual({ track: 0, insertRow: null });
+  });
+
+  it("relocates DOWN when the tracks above are also occupied", () => {
+    expect(
+      resolveZoneDropPlacement({
+        ...base,
+        elements: [el("a", 0, 0, 5), el("b", 1, 0, 5)],
+        desiredTrack: 1,
+      }),
+    ).toEqual({ track: 2, insertRow: null });
+  });
+
+  it("auto-creates a new track when EVERY lane in the zone is occupied at that time", () => {
+    expect(
+      resolveZoneDropPlacement({
+        ...base,
+        elements: [el("a", 0, 0, 5), el("b", 1, 0, 5), el("c", 2, 0, 5)],
+        desiredTrack: 1,
+      }),
+    ).toEqual({ track: 1, insertRow: 2 });
+  });
+
+  // Every visual lane (0,1,2) occupied across the drop span → no free lane exists.
+  const allVisualOccupied = () => [el("a", 0, 0, 10), el("b", 1, 0, 10), el("c", 2, 0, 10)];
+
+  it("occupied aim with NO free lane creates an adjacent track — never snaps back (UX rule 3)", () => {
+    // The clip must NOT return to its origin; it gets a fresh track adjacent to the
+    // aim. Default bias = below the aimed row.
+    const result = resolveZoneDropPlacement({
+      ...base,
+      elements: allVisualOccupied(),
+      desiredTrack: 1,
+    });
+    expect(result.insertRow).not.toBeNull(); // a track is created, not an origin snap-back
+    expect(result).toEqual({ track: 1, insertRow: 2 }); // adjacent, below the aimed row
+  });
+
+  it("opens the new adjacent track ABOVE the aimed row when the pointer is in its upper half (UX rule 3)", () => {
+    expect(
+      resolveZoneDropPlacement({
+        ...base,
+        elements: allVisualOccupied(),
+        desiredTrack: 1,
+        preferInsertAbove: true,
+      }),
+    ).toEqual({ track: 1, insertRow: 1 }); // boundary ABOVE lane 1
+    // Same aim, pointer in the lower half → the track opens BELOW the aimed row.
+    expect(
+      resolveZoneDropPlacement({
+        ...base,
+        elements: allVisualOccupied(),
+        desiredTrack: 1,
+        preferInsertAbove: false,
+      }),
+    ).toEqual({ track: 1, insertRow: 2 });
+  });
+
+  it("shares a track for sequential (non-overlapping) clips", () => {
+    expect(
+      resolveZoneDropPlacement({
+        ...base,
+        elements: [el("a", 1, 0, 2)],
+        desiredTrack: 1,
+        start: 2,
+      }),
+    ).toEqual({ track: 1, insertRow: null });
+  });
+
+  it("clamps a visual clip OUT of the audio zone before placing", () => {
+    expect(resolveZoneDropPlacement({ ...base, elements: [], desiredTrack: 3 })).toEqual({
+      track: 2,
+      insertRow: null,
+    });
+  });
+
+  it("clamps an audio clip INTO the audio zone before placing", () => {
+    expect(
+      resolveZoneDropPlacement({ ...base, elements: [], desiredTrack: 0, isAudio: true }),
+    ).toEqual({ track: 3, insertRow: null });
+  });
+
+  it("upward create-drag off the top lane inserts at the TOP of the visual zone, never below audio (reviewer repro)", () => {
+    // 3-visual + 1-audio timeline. Dragging a top-lane visual clip up past the
+    // create threshold emits the sentinel desiredTrack = minTrack-1 = -1. The
+    // old hoist did order.indexOf(-1) = -1 and fell to below = order.length = 4,
+    // creating the new track BELOW the audio zone — repro {track:-1, insertRow:4}.
+    // It must now anchor to the top boundary of the visual zone.
+    expect(
+      resolveZoneDropPlacement({ ...base, elements: allVisualOccupied(), desiredTrack: -1 }),
+    ).toEqual({ track: -1, insertRow: 0 });
+  });
+
+  it("downward create-drag off the bottom visual lane inserts at the audio boundary, never below it", () => {
+    // Sentinel desiredTrack = maxTrack+1 = 4 for a downward create-drag. A visual
+    // clip must land at the bottom of the visual zone (row 3 = just above audio),
+    // not past the audio lanes.
+    expect(
+      resolveZoneDropPlacement({ ...base, elements: allVisualOccupied(), desiredTrack: 4 }),
+    ).toEqual({ track: 4, insertRow: 3 });
+  });
+
+  it("audio create-drag with an out-of-range aim inserts inside the audio zone", () => {
+    // An audio clip aimed above its zone (sentinel below its own min lane) anchors
+    // to the audio zone's top boundary (row 3), not into the visual zone.
+    expect(
+      resolveZoneDropPlacement({
+        ...base,
+        elements: [el("a", 3, 0, 10)],
+        desiredTrack: -1,
+        isAudio: true,
+      }),
+    ).toEqual({ track: -1, insertRow: 3 });
+  });
+
+  it("honors a deliberate boundary insert in the clip's own zone", () => {
+    expect(
+      resolveZoneDropPlacement({ ...base, elements: [], desiredTrack: 1, deliberateInsertRow: 1 }),
+    ).toEqual({ track: 1, insertRow: 1 });
+  });
+
+  it("ignores a deliberate insert that lands in the WRONG zone (visual into audio)", () => {
+    expect(
+      resolveZoneDropPlacement({ ...base, elements: [], desiredTrack: 1, deliberateInsertRow: 4 }),
+    ).toEqual({ track: 1, insertRow: null });
+  });
+
+  it("lets an AUDIO clip create a new audio track via a boundary insert", () => {
+    expect(
+      resolveZoneDropPlacement({
+        ...base,
+        elements: [],
+        desiredTrack: 3,
+        isAudio: true,
+        deliberateInsertRow: 4,
+      }),
+    ).toEqual({ track: 3, insertRow: 4 });
+  });
+
+  it("Abhai repro: audio dropped on a visual-only timeline over an occupied span → insert, no overlap (#2195)", () => {
+    // No audio zone exists yet (audioTracks empty). The audio clip is aimed at the
+    // sole visual lane, which is occupied at the drop time. The zone-drop must
+    // create the audio zone's first lane (insertRow set) rather than stacking the
+    // audio clip onto the occupied visual track — the no-overlap invariant.
+    const result = resolveZoneDropPlacement({
+      order: [0],
+      audioTracks: new Set<number>(),
+      elements: [el("v", 0, 0, 5)],
+      desiredTrack: 0,
+      deliberateInsertRow: null,
+      start: 1,
+      duration: 2,
+      dragKey: "audio",
+      isAudio: true,
+    });
+    expect(result.insertRow).not.toBeNull();
+    expect(result).toEqual({ track: 0, insertRow: 1 });
+  });
+
+  it("free-span repro: audio dropped on a FREE stretch of a visual-only timeline → insert, not a visual lane (#2195)", () => {
+    // Same visual-only timeline, but the audio clip is aimed at a stretch the sole
+    // visual lane is FREE at. The zone check must still fire an insert (create the
+    // audio zone) rather than short-circuiting on isLaneFree and dropping the audio
+    // clip onto the visual lane — the kind-zone hole where the free-lane fast path
+    // beat the wrong-zone check.
+    const result = resolveZoneDropPlacement({
+      order: [0],
+      audioTracks: new Set<number>(),
+      elements: [el("v", 0, 0, 5)],
+      desiredTrack: 0,
+      deliberateInsertRow: null,
+      start: 10, // past the visual clip's end → the visual lane is FREE here
+      duration: 2,
+      dragKey: "audio",
+      isAudio: true,
+    });
+    expect(result.insertRow).not.toBeNull();
+    expect(result).toEqual({ track: 0, insertRow: 1 });
+  });
+});
diff --git a/packages/studio/src/player/components/timelineCollision.ts b/packages/studio/src/player/components/timelineCollision.ts
new file mode 100644
index 0000000000..6dce919ec9
--- /dev/null
+++ b/packages/studio/src/player/components/timelineCollision.ts
@@ -0,0 +1,263 @@
+import type { TimelineElement } from "../store/playerStore";
+
+/**
+ * Keep a landing track inside the dragged clip's kind-zone: visual clips stay in
+ * the rows ABOVE the first audio lane; audio clips stay AT/BELOW it. Prevents a
+ * clip from appearing to land in the wrong zone mid-drag (which normalizeToZones
+ * would then snap back). `audioRow` = index in `trackOrder` of the first audio
+ * lane, or -1 when there is no audio zone yet (then it's a no-op).
+ */
+export function clampTrackToZone(
+  targetTrack: number,
+  trackOrder: number[],
+  audioRow: number,
+  isAudio: boolean,
+): number {
+  if (audioRow < 0) return targetTrack;
+  const row = trackOrder.indexOf(targetTrack);
+  if (row < 0) return targetTrack;
+  if (isAudio) return row >= audioRow ? targetTrack : (trackOrder[audioRow] ?? targetTrack);
+  return row < audioRow ? targetTrack : (trackOrder[audioRow - 1] ?? targetTrack);
+}
+
+/**
+ * Whether a new-track insert at boundary `insertRow` is allowed for a clip of the
+ * given kind. Visual clips may only insert visual lanes (boundary at/above the top
+ * of the audio zone); audio clips may only insert audio lanes (boundary at/below
+ * it) — so audio clips CAN create a new audio track, and neither kind inserts into
+ * the other's zone. `audioRow` = first audio lane row, or -1 (no audio zone) → any.
+ */
+export function isInsertAllowedForZone(
+  insertRow: number,
+  audioRow: number,
+  isAudio: boolean,
+): boolean {
+  if (audioRow < 0) return true;
+  return isAudio ? insertRow >= audioRow : insertRow <= audioRow;
+}
+
+/**
+ * The full drop-placement decision for a dragged clip — one pure, testable unit.
+ * Enforces: NO time-overlap on a single track; a clip stays in its kind-zone;
+ * a new track is created only when needed. Order of resolution:
+ *   1. Deliberate boundary insert (pointer near a lane edge), if it's in the
+ *      clip's own zone → create a new track there.
+ *   2. Otherwise land on a lane: clamp the aimed track to the clip's zone, take it
+ *      if free at [start, start+duration), else the nearest FREE lane in the zone
+ *      (prefer up), else auto-create a new track right below the aimed lane.
+ * `audioTracks` = the set of track indices that currently hold audio (so the fn
+ * needs no element-kind import). Returns the landing `track` and, when a new track
+ * should be created, the `insertRow` boundary (else null).
+ *
+ * `preferInsertAbove` biases the auto-created track (occupied-aim → new adjacent
+ * track) toward the boundary ABOVE the aimed row instead of below it, so the new
+ * lane opens on whichever side of the aimed clip the pointer is nearer (the drag
+ * preview passes the pointer's sub-row half). A clip whose aimed span is occupied
+ * never snaps back to its origin — it relocates to a free lane, or (none free)
+ * gets a fresh track next to the aim. Default (below) preserves prior behaviour.
+ */
+/**
+ * Insert-row boundary for an out-of-range aim — a `desired` track that isn't a
+ * real lane: the sentinel minTrack-1 an upward create-drag emits (#2214-adjacent
+ * repro) or a beyond-the-bottom index a downward one does. Anchors the new track
+ * to a boundary of the clip's OWN kind-zone so a visual insert can never land
+ * past the audio zone (the old below = order.length fallback dropped it BELOW the
+ * audio lanes). Above the zone (`desired` < the zone's min lane) → the zone's TOP
+ * boundary; otherwise → its BOTTOM boundary (for a visual clip, the top of the
+ * audio zone). `zoneTracks` = this kind's lanes, in `order` sequence.
+ */
+function outOfRangeZoneInsertRow(
+  order: number[],
+  zoneTracks: number[],
+  audioRow: number,
+  desired: number,
+): number {
+  // No lane of this kind yet: fall to the split (audioRow) or the very top.
+  // A visual-only timeline has audioRow -1 (top); an all-audio one has it at 0.
+  if (zoneTracks.length === 0) return audioRow < 0 ? 0 : audioRow;
+  // zoneTracks preserves `order` sequence, so its ends map to the zone boundary
+  // rows: above the zone's min lane → its top boundary, else its bottom.
+  const zoneTop = order.indexOf(zoneTracks[0]);
+  const zoneBottom = order.indexOf(zoneTracks[zoneTracks.length - 1]) + 1;
+  return desired < Math.min(...zoneTracks) ? zoneTop : zoneBottom;
+}
+
+export function resolveZoneDropPlacement(input: {
+  order: number[];
+  audioTracks: ReadonlySet<number>;
+  elements: TimelineElement[];
+  desiredTrack: number;
+  deliberateInsertRow: number | null;
+  start: number;
+  duration: number;
+  dragKey: string;
+  isAudio: boolean;
+  preferInsertAbove?: boolean;
+}): { track: number; insertRow: number | null } {
+  const { order, audioTracks, elements, desiredTrack, deliberateInsertRow } = input;
+  const { start, duration, dragKey, isAudio, preferInsertAbove } = input;
+  const audioRow = order.findIndex((t) => audioTracks.has(t));
+
+  if (
+    deliberateInsertRow !== null &&
+    isInsertAllowedForZone(deliberateInsertRow, audioRow, isAudio)
+  ) {
+    return { track: desiredTrack, insertRow: deliberateInsertRow };
+  }
+
+  const desired = clampTrackToZone(desiredTrack, order, audioRow, isAudio);
+  const zoneTracks = order.filter((t) => audioTracks.has(t) === isAudio);
+  const placement = resolvePlacement({
+    elements,
+    desiredTrack: desired,
+    start,
+    duration,
+    trackOrder: zoneTracks,
+    excludeKey: dragKey,
+  });
+  if (placement.needsInsert) {
+    const desiredRow = order.indexOf(desired);
+    if (desiredRow < 0) {
+      return {
+        track: desired,
+        insertRow: outOfRangeZoneInsertRow(order, zoneTracks, audioRow, desired),
+      };
+    }
+    // Prefer the gap NEAREST the pointer: insert above the aimed row when the
+    // pointer sits in its upper half AND that boundary is in the clip's own zone
+    // (else the visual/audio split would be crossed) — otherwise fall to below.
+    // `desired` is clamped into the zone, so both boundaries stay in-zone.
+    const insertRow =
+      preferInsertAbove && isInsertAllowedForZone(desiredRow, audioRow, isAudio)
+        ? desiredRow
+        : desiredRow + 1;
+    return { track: desired, insertRow };
+  }
+  return { track: placement.track, insertRow: null };
+}
+
+/**
+ * Fallback half-width (fraction of a track height) of the insert band straddling
+ * a lane boundary — used only when the caller passes no explicit band. Production
+ * threads the geometry-exact `INSERT_BOUNDARY_BAND` (timelineLayout.ts, = the clip
+ * inset `CLIP_Y / TRACK_H`) so the band matches the rendered inter-clip gutter and
+ * NEVER reaches into a clip body. Kept in sync with that constant; do not widen it
+ * back toward the old 0.32 (which armed an insert across ~64% of every row — the
+ * misfire that turned a plain horizontal drag into a phantom track insert).
+ */
+const INSERT_BAND = 3 / 48;
+
+/**
+ * Decide whether a vertical drag is inserting a new track at a lane boundary.
+ * `rowFloat` is the pointer's position in track-height units from the top of the
+ * first lane (0 = top of lane 0). Returns the boundary row to insert at
+ * (0 = above the top lane, `trackCount` = below the bottom), or null when the
+ * pointer is over a lane's middle band (a normal move/target).
+ */
+export function resolveInsertRow(
+  rowFloat: number,
+  trackCount: number,
+  band: number = INSERT_BAND,
+): number | null {
+  if (trackCount === 0) return 0;
+  if (rowFloat <= 0) return 0;
+  if (rowFloat >= trackCount) return trackCount;
+  const lane = Math.floor(rowFloat);
+  const frac = rowFloat - lane;
+  if (frac < band) return lane;
+  if (frac > 1 - band) return lane + 1;
+  return null;
+}
+
+/** Half-open overlap test: [aStart, aEnd) intersects [bStart, bEnd). */
+export function timeRangesOverlap(
+  aStart: number,
+  aEnd: number,
+  bStart: number,
+  bEnd: number,
+): boolean {
+  return aStart < bEnd && bStart < aEnd;
+}
+
+/**
+ * True when no clip on `track` overlaps [start, end) — excluding the clip
+ * identified by `excludeKey` (the one being dragged).
+ */
+export function isLaneFree(
+  elements: TimelineElement[],
+  track: number,
+  start: number,
+  end: number,
+  excludeKey: string | null,
+): boolean {
+  return !elements.some(
+    (el) =>
+      (el.key ?? el.id) !== excludeKey &&
+      el.track === track &&
+      timeRangesOverlap(start, end, el.start, el.start + el.duration),
+  );
+}
+
+export interface PlacementInput {
+  elements: TimelineElement[];
+  desiredTrack: number;
+  start: number;
+  duration: number;
+  trackOrder: number[];
+  excludeKey: string | null;
+}
+
+export interface PlacementResult {
+  /** The lane the clip should land on. */
+  track: number;
+  /**
+   * True when no existing lane was free and the caller should insert a new
+   * track instead of landing on `track` (which is then the desired lane as a
+   * last-resort fallback). Consumed in later stages (2b/2c); stage 2a ignores it.
+   */
+  needsInsert: boolean;
+}
+
+/**
+ * Resolve where a dragged clip should land, avoiding overlap. If the desired
+ * lane is free, keep it. Otherwise search the nearest free lane, **preferring
+ * up** (all lanes above, nearest first), then down. If none is free, signal an
+ * insert and fall back to the desired lane.
+ */
+export function resolvePlacement({
+  elements,
+  desiredTrack,
+  start,
+  duration,
+  trackOrder,
+  excludeKey,
+}: PlacementInput): PlacementResult {
+  const end = start + duration;
+  const idx = trackOrder.indexOf(desiredTrack);
+  // desiredTrack is not one of the zone's lanes — the clip's kind-zone has no lane
+  // yet (e.g. an audio clip dropped on a visual-only timeline). This MUST be checked
+  // BEFORE the isLaneFree short-circuit below: a free-aimed span on a foreign-zone
+  // lane (an audio clip aimed at an empty stretch of a visual-only timeline) is
+  // "free" only because that lane belongs to the wrong zone. Landing there would
+  // put the clip in the wrong kind-zone, so signal an insert to create the zone's
+  // first lane instead — regardless of whether the aimed span is occupied (#2195).
+  if (idx === -1) return { track: desiredTrack, needsInsert: true };
+
+  if (isLaneFree(elements, desiredTrack, start, end, excludeKey)) {
+    return { track: desiredTrack, needsInsert: false };
+  }
+
+  // Prefer up: nearest lane above first, then the rest above.
+  for (let up = idx - 1; up >= 0; up--) {
+    if (isLaneFree(elements, trackOrder[up], start, end, excludeKey)) {
+      return { track: trackOrder[up], needsInsert: false };
+    }
+  }
+  // Then down: nearest lane below first.
+  for (let down = idx + 1; down < trackOrder.length; down++) {
+    if (isLaneFree(elements, trackOrder[down], start, end, excludeKey)) {
+      return { track: trackOrder[down], needsInsert: false };
+    }
+  }
+  return { track: desiredTrack, needsInsert: true };
+}