diff --git a/packages/studio/src/index.ts b/packages/studio/src/index.ts
index 5ead3f48b..73d710490 100644
--- a/packages/studio/src/index.ts
+++ b/packages/studio/src/index.ts
@@ -10,13 +10,12 @@ export {
   PlayerControls,
   Timeline,
   PreviewPanel,
-  AgentActivityTrack,
   useTimelinePlayer,
   usePlayerStore,
   liveTime,
   formatTime,
 } from "./player";
-export type { AgentActivity, TimelineElement, ActiveEdits } from "./player";
+export type { TimelineElement, ZoomMode } from "./player";
 
 // Editor
 export { SourceEditor } from "./components/editor/SourceEditor";
diff --git a/packages/studio/src/player/components/Timeline.tsx b/packages/studio/src/player/components/Timeline.tsx
index 8fdb50cb3..8f79f4145 100644
--- a/packages/studio/src/player/components/Timeline.tsx
+++ b/packages/studio/src/player/components/Timeline.tsx
@@ -163,7 +163,6 @@ export const Timeline = memo(function Timeline({ onSeek, onDrillDown }: Timeline
   const timelineReady = usePlayerStore((s) => s.timelineReady);
   const selectedElementId = usePlayerStore((s) => s.selectedElementId);
   const setSelectedElementId = usePlayerStore((s) => s.setSelectedElementId);
-  const activeEdits = usePlayerStore((s) => s.activeEdits);
   const playheadRef = useRef<HTMLDivElement>(null);
   const containerRef = useRef<HTMLDivElement>(null);
   const [hoveredClip, setHoveredClip] = useState<string | null>(null);
@@ -348,8 +347,6 @@ export const Timeline = memo(function Timeline({ onSeek, onDrillDown }: Timeline
                   const isComposition = !!el.compositionSrc;
                   const clipKey = `${el.id}-${i}`;
                   const isHovered = hoveredClip === clipKey;
-                  const activeEdit = activeEdits[el.id];
-                  const isBeingEdited = !!activeEdit;
 
                   return (
                     <div
@@ -371,11 +368,9 @@ export const Timeline = memo(function Timeline({ onSeek, onDrillDown }: Timeline
                           : `1px solid rgba(255,255,255,${isHovered ? 0.3 : 0.15})`,
                         boxShadow: isSelected
                           ? `0 0 0 1px ${style.clip}, 0 2px 8px rgba(0,0,0,0.4)`
-                          : isBeingEdited
-                            ? `0 0 0 1px ${activeEdit.agentColor}80, 0 0 8px ${activeEdit.agentColor}40`
-                            : isHovered
-                              ? "0 1px 4px rgba(0,0,0,0.3)"
-                              : "none",
+                          : isHovered
+                            ? "0 1px 4px rgba(0,0,0,0.3)"
+                            : "none",
                         cursor: "pointer",
                         transition: "border-color 120ms, box-shadow 120ms, transform 80ms",
                         transform: isHovered && !isSelected ? "scaleY(1.04)" : "scaleY(1)",
@@ -400,59 +395,6 @@ export const Timeline = memo(function Timeline({ onSeek, onDrillDown }: Timeline
                         }
                       }}
                     >
-                      {/* Agent ownership dot */}
-                      {el.agentColor && (
-                        <div
-                          className="flex-shrink-0 w-1.5 h-1.5 rounded-full ml-1"
-                          style={{ backgroundColor: el.agentColor }}
-                          title={el.agentId ? `Agent: ${el.agentId}` : undefined}
-                        />
-                      )}
-                      {/* Editing glow pulse */}
-                      {/* Agent editing indicator — cursor on the clip */}
-                      {isBeingEdited && (
-                        <>
-                          <div
-                            className="absolute inset-0 rounded-[5px] animate-pulse pointer-events-none"
-                            style={{ boxShadow: `inset 0 0 0 1px ${activeEdit.agentColor}60` }}
-                          />
-                          {/* Agent name badge above clip */}
-                          <div
-                            className="absolute pointer-events-none flex items-center gap-1"
-                            style={{
-                              top: -16,
-                              left: 2,
-                              zIndex: 30,
-                            }}
-                          >
-                            {/* Mini cursor arrow */}
-                            <svg
-                              width="8"
-                              height="10"
-                              viewBox="0 0 12 16"
-                              fill="none"
-                              style={{ flexShrink: 0 }}
-                            >
-                              <path
-                                d="M1 1L11 7L6 8L4 14L1 1Z"
-                                fill={activeEdit.agentColor}
-                                stroke="white"
-                                strokeWidth="0.8"
-                              />
-                            </svg>
-                            <span
-                              className="text-[8px] font-semibold px-1 py-px rounded whitespace-nowrap"
-                              style={{
-                                backgroundColor: activeEdit.agentColor,
-                                color: "white",
-                                boxShadow: `0 1px 4px ${activeEdit.agentColor}40`,
-                              }}
-                            >
-                              {activeEdit.agentId}
-                            </span>
-                          </div>
-                        </>
-                      )}
                       <span
                         className="text-[10px] font-semibold truncate px-1.5 leading-none"
                         style={{ color: style.label }}
diff --git a/packages/studio/src/player/index.ts b/packages/studio/src/player/index.ts
index f17928567..4318cf39f 100644
--- a/packages/studio/src/player/index.ts
+++ b/packages/studio/src/player/index.ts
@@ -3,15 +3,13 @@ export { Player } from "./components/Player";
 export { PlayerControls } from "./components/PlayerControls";
 export { Timeline } from "./components/Timeline";
 export { PreviewPanel } from "./components/PreviewPanel";
-export { AgentActivityTrack } from "./components/AgentActivityTrack";
-export type { AgentActivity } from "./components/AgentActivityTrack";
 
 // Hooks
 export { useTimelinePlayer } from "./hooks/useTimelinePlayer";
 
 // Store
 export { usePlayerStore, liveTime } from "./store/playerStore";
-export type { TimelineElement, ActiveEdits } from "./store/playerStore";
+export type { TimelineElement, ZoomMode } from "./store/playerStore";
 
 // Utils
 export { formatTime } from "./lib/time";
diff --git a/packages/studio/src/player/store/playerStore.ts b/packages/studio/src/player/store/playerStore.ts
index 811cea554..89eb44df2 100644
--- a/packages/studio/src/player/store/playerStore.ts
+++ b/packages/studio/src/player/store/playerStore.ts
@@ -11,16 +11,9 @@ export interface TimelineElement {
   volume?: number;
   /** Path from data-composition-src — identifies sub-composition elements */
   compositionSrc?: string;
-  /** Agent that created/last edited this element */
-  agentId?: string;
-  /** Agent's color for ownership visualization */
-  agentColor?: string;
 }
 
-/** Map of elementId → agentColor for clips currently being edited */
-export interface ActiveEdits {
-  [elementId: string]: { agentId: string; agentColor: string };
-}
+export type ZoomMode = "fit" | "manual";
 
 interface PlayerState {
   isPlaying: boolean;
@@ -29,9 +22,15 @@ interface PlayerState {
   timelineReady: boolean;
   elements: TimelineElement[];
   selectedElementId: string | null;
-  /** Clips currently being edited by agents — for glow animation */
-  activeEdits: ActiveEdits;
   playbackRate: number;
+  /** Timeline zoom: 'fit' auto-scales to viewport, 'manual' uses pixelsPerSecond */
+  zoomMode: ZoomMode;
+  /** Pixels per second when in manual zoom mode */
+  pixelsPerSecond: number;
+  /** Edit range selection */
+  editRangeStart: number | null;
+  editRangeEnd: number | null;
+  editMode: boolean;
 
   setIsPlaying: (playing: boolean) => void;
   setCurrentTime: (time: number) => void;
@@ -40,8 +39,17 @@ interface PlayerState {
   setTimelineReady: (ready: boolean) => void;
   setElements: (elements: TimelineElement[]) => void;
   setSelectedElementId: (id: string | null) => void;
-  setActiveEdits: (edits: ActiveEdits) => void;
+  setEditRange: (start: number | null, end: number | null) => void;
+  setEditMode: (active: boolean) => void;
   updateElementStart: (elementId: string, newStart: number) => void;
+  updateElementDuration: (elementId: string, newDuration: number) => void;
+  updateElementTrack: (elementId: string, newTrack: number) => void;
+  updateElement: (
+    elementId: string,
+    updates: Partial<Pick<TimelineElement, "start" | "duration" | "track">>,
+  ) => void;
+  setZoomMode: (mode: ZoomMode) => void;
+  setPixelsPerSecond: (pps: number) => void;
   reset: () => void;
 }
 
@@ -65,21 +73,42 @@ export const usePlayerStore = create<PlayerState>((set) => ({
   timelineReady: false,
   elements: [],
   selectedElementId: null,
-  activeEdits: {},
   playbackRate: 1,
+  zoomMode: "fit",
+  pixelsPerSecond: 100,
+  editRangeStart: null,
+  editRangeEnd: null,
+  editMode: false,
 
   setIsPlaying: (playing) => set({ isPlaying: playing }),
   setPlaybackRate: (rate) => set({ playbackRate: rate }),
-  setCurrentTime: (time) => set({ currentTime: time }),
-  setDuration: (duration) => set({ duration }),
+  setZoomMode: (mode) => set({ zoomMode: mode }),
+  setPixelsPerSecond: (pps) => set({ pixelsPerSecond: Math.max(10, pps) }),
+  setCurrentTime: (time) => set({ currentTime: Number.isFinite(time) ? time : 0 }),
+  setDuration: (duration) => set({ duration: Number.isFinite(duration) ? duration : 0 }),
   setTimelineReady: (ready) => set({ timelineReady: ready }),
   setElements: (elements) => set({ elements }),
   setSelectedElementId: (id) => set({ selectedElementId: id }),
-  setActiveEdits: (edits) => set({ activeEdits: edits }),
+  setEditRange: (start, end) => set({ editRangeStart: start, editRangeEnd: end }),
+  setEditMode: (active) => set({ editMode: active, editRangeStart: null, editRangeEnd: null }),
   updateElementStart: (elementId, newStart) =>
     set((state) => ({
       elements: state.elements.map((el) => (el.id === elementId ? { ...el, start: newStart } : el)),
     })),
+  updateElementDuration: (elementId, newDuration) =>
+    set((state) => ({
+      elements: state.elements.map((el) =>
+        el.id === elementId ? { ...el, duration: newDuration } : el,
+      ),
+    })),
+  updateElementTrack: (elementId, newTrack) =>
+    set((state) => ({
+      elements: state.elements.map((el) => (el.id === elementId ? { ...el, track: newTrack } : el)),
+    })),
+  updateElement: (elementId, updates) =>
+    set((state) => ({
+      elements: state.elements.map((el) => (el.id === elementId ? { ...el, ...updates } : el)),
+    })),
   reset: () =>
     set({
       isPlaying: false,
@@ -88,6 +117,5 @@ export const usePlayerStore = create<PlayerState>((set) => ({
       timelineReady: false,
       elements: [],
       selectedElementId: null,
-      activeEdits: {},
     }),
 }));