Fix auto-compaction TUI integration and cut point logic

- Trigger auto-compaction after agent_end instead of during message_end
- Show CompactionComponent after auto-compaction (same as manual /compact)
- Fix cut point to include bash executions before kept user message
- Stop backward scan at compaction, assistant, user, or toolResult boundaries

packages/coding-agent/src/core/agent-session.ts

@@ -135,6 +135,9 @@ export class AgentSession {
 		}
 	}
 
+	// Track last assistant message for auto-compaction check
+	private _lastAssistantMessage: AssistantMessage | null = null;
+
 	/** Internal handler for agent events - shared by subscribe and reconnect */
 	private _handleAgentEvent = async (event: AgentEvent): Promise<void> => {
 		// Notify all listeners
@@ -149,11 +152,18 @@ export class AgentSession {
 				this.sessionManager.startSession(this.agent.state);
 			}
 
-			// Check auto-compaction after assistant messages
+			// Track assistant message for auto-compaction (checked on agent_end)
 			if (event.message.role === "assistant") {
-				await this._runAutoCompaction();
+				this._lastAssistantMessage = event.message as AssistantMessage;
 			}
 		}
+
+		// Check auto-compaction after agent completes (after agent_end clears UI)
+		if (event.type === "agent_end" && this._lastAssistantMessage) {
+			const msg = this._lastAssistantMessage;
+			this._lastAssistantMessage = null;
+			this._runAutoCompaction(msg).catch(() => {});
+		}
 	};
 
 	/**
@@ -584,26 +594,14 @@ export class AgentSession {
 	 * Internal: Run auto-compaction with events.
 	 * Called after assistant messages complete.
 	 */
-	private async _runAutoCompaction(): Promise<void> {
+	private async _runAutoCompaction(assistantMessage: AssistantMessage): Promise<void> {
 		const settings = this.settingsManager.getCompactionSettings();
 		if (!settings.enabled) return;
 
-		// Get last non-aborted assistant message
-		const messages = this.messages;
-		let lastAssistant: AssistantMessage | null = null;
-		for (let i = messages.length - 1; i >= 0; i--) {
-			const msg = messages[i];
-			if (msg.role === "assistant") {
-				const assistantMsg = msg as AssistantMessage;
-				if (assistantMsg.stopReason !== "aborted") {
-					lastAssistant = assistantMsg;
-					break;
-				}
-			}
-		}
-		if (!lastAssistant) return;
+		// Skip if message was aborted
+		if (assistantMessage.stopReason === "aborted") return;
 
-		const contextTokens = calculateContextTokens(lastAssistant.usage);
+		const contextTokens = calculateContextTokens(assistantMessage.usage);
 		const contextWindow = this.model?.contextWindow ?? 0;
 
 		if (!shouldCompact(contextTokens, contextWindow, settings)) return;
@@ -624,6 +622,7 @@ export class AgentSession {
 				return;
 			}
 
+			// Load entries (sync file read) then yield to let UI render
 			const entries = this.sessionManager.loadEntries();
 			const compactionEntry = await compact(
 				entries,

packages/coding-agent/src/core/compaction.ts

@@ -94,7 +94,11 @@ function findTurnBoundaries(entries: SessionEntry[], startIndex: number, endInde
 
 /**
  * Find the cut point in session entries that keeps approximately `keepRecentTokens`.
- * Returns the entry index of the first message to keep (a user message for turn integrity).
+ * Returns the entry index of the first entry to keep.
+ *
+ * The cut point targets a user message (turn boundary), but then scans backwards
+ * to include any preceding non-turn entries (bash executions, settings changes, etc.)
+ * that should logically be part of the kept context.
  *
  * Only considers entries between `startIndex` and `endIndex` (exclusive).
  */
@@ -150,6 +154,25 @@ export function findCutPoint(
 		}
 	}
 
+	// Scan backwards from cutIndex to include any non-turn entries (bash, settings, etc.)
+	// that should logically be part of the kept context
+	while (cutIndex > startIndex) {
+		const prevEntry = entries[cutIndex - 1];
+		// Stop at compaction boundaries
+		if (prevEntry.type === "compaction") {
+			break;
+		}
+		if (prevEntry.type === "message") {
+			const role = prevEntry.message.role;
+			// Stop if we hit an assistant, user, or tool result (all part of previous turn)
+			if (role === "assistant" || role === "user" || role === "toolResult") {
+				break;
+			}
+		}
+		// Include this non-turn entry (bash, settings change, etc.)
+		cutIndex--;
+	}
+
 	return cutIndex;
 }
 

packages/coding-agent/src/modes/interactive/interactive-mode.ts

@@ -597,7 +597,11 @@ export class InteractiveMode {
 					// Rebuild chat to show compacted state
 					this.chatContainer.clear();
 					this.rebuildChatFromMessages();
-					this.showStatus(`Auto-compacted: ${event.result.tokensBefore.toLocaleString()} tokens`);
+					// Add compaction component (same as manual /compact)
+					const compactionComponent = new CompactionComponent(event.result.tokensBefore, event.result.summary);
+					compactionComponent.setExpanded(this.toolOutputExpanded);
+					this.chatContainer.addChild(compactionComponent);
+					this.footer.updateState(this.session.state);
 				}
 				this.ui.requestRender();
 				break;