chore(compaction): add E2E compaction benchmark script

Multi-turn test script for compaction behavior with low context window.
Runs 4 turns of file reading to push context pressure and outputs
run-log analysis.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

scripts/compaction-benchmark/run.sh

@@ -0,0 +1,137 @@
+#!/usr/bin/env bash
+# Compaction Benchmark - Multi-turn test with low context window
+#
+# This script runs a series of prompts against the Multica agent with a very
+# low context window (20k tokens) to force compaction to trigger quickly.
+# The run-log output is then available for analysis.
+#
+# Usage:
+#   bash scripts/compaction-benchmark/run.sh [provider]
+#
+# Default provider: kimi-coding
+
+set -euo pipefail
+
+PROVIDER="${1:-kimi-coding}"
+CONTEXT_WINDOW="${2:-20000}"
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+ROOT_DIR="$(cd "$SCRIPT_DIR/../.." && pwd)"
+
+export SMC_DATA_DIR=~/.super-multica-e2e
+
+echo "=== Compaction Benchmark ==="
+echo "Provider: $PROVIDER"
+echo "Context Window: $CONTEXT_WINDOW tokens"
+echo "Data Dir: $SMC_DATA_DIR"
+echo ""
+
+# Clean previous E2E data
+rm -rf "$SMC_DATA_DIR"
+
+cd "$ROOT_DIR"
+
+# Turn 1: Start a session with a substantial prompt that generates tool usage
+echo "--- Turn 1: Initial prompt (read multiple files) ---"
+TURN1_OUTPUT=$(SMC_DATA_DIR="$SMC_DATA_DIR" pnpm multica run \
+  --run-log \
+  --provider "$PROVIDER" \
+  --context-window "$CONTEXT_WINDOW" \
+  "Read the following files and give me a brief summary of each: packages/core/src/agent/runner.ts, packages/core/src/agent/session/session-manager.ts, packages/core/src/agent/context-window/token-estimation.ts. List the main exports and key functions in each file." \
+  2>&1)
+
+# Extract session ID from stderr output
+SESSION_ID=$(echo "$TURN1_OUTPUT" | grep -o '\[session: [^]]*\]' | head -1 | sed 's/\[session: //;s/\]//')
+SESSION_DIR=$(echo "$TURN1_OUTPUT" | grep -o '\[session-dir: [^]]*\]' | head -1 | sed 's/\[session-dir: //;s/\]//')
+
+if [ -z "$SESSION_ID" ]; then
+  echo "ERROR: Could not extract session ID from output"
+  echo "$TURN1_OUTPUT"
+  exit 1
+fi
+
+echo "Session ID: $SESSION_ID"
+echo "Session Dir: $SESSION_DIR"
+echo ""
+
+# Turn 2: Continue the session with more file reads to push context higher
+echo "--- Turn 2: More file reads (push context higher) ---"
+TURN2_OUTPUT=$(SMC_DATA_DIR="$SMC_DATA_DIR" pnpm multica run \
+  --run-log \
+  --provider "$PROVIDER" \
+  --context-window "$CONTEXT_WINDOW" \
+  --session "$SESSION_ID" \
+  "Now also read packages/core/src/agent/context-window/summarization.ts and packages/core/src/agent/context-window/tool-result-pruning.ts. Describe the key algorithms in each." \
+  2>&1)
+
+echo "$TURN2_OUTPUT" | head -5
+echo ""
+
+# Turn 3: More context-heavy work
+echo "--- Turn 3: Additional analysis (should trigger compaction) ---"
+TURN3_OUTPUT=$(SMC_DATA_DIR="$SMC_DATA_DIR" pnpm multica run \
+  --run-log \
+  --provider "$PROVIDER" \
+  --context-window "$CONTEXT_WINDOW" \
+  --session "$SESSION_ID" \
+  "Read packages/core/src/agent/session/compaction.ts and explain the three compaction modes. Also read packages/core/src/agent/context-window/guard.ts and explain the guard thresholds." \
+  2>&1)
+
+echo "$TURN3_OUTPUT" | head -5
+echo ""
+
+# Turn 4: More tool usage
+echo "--- Turn 4: Write and test (more context pressure) ---"
+TURN4_OUTPUT=$(SMC_DATA_DIR="$SMC_DATA_DIR" pnpm multica run \
+  --run-log \
+  --provider "$PROVIDER" \
+  --context-window "$CONTEXT_WINDOW" \
+  --session "$SESSION_ID" \
+  "Based on everything you've read so far, list all the constants and thresholds used in the compaction system. Provide exact values and which file each is defined in." \
+  2>&1)
+
+echo "$TURN4_OUTPUT" | head -5
+echo ""
+
+# Output analysis summary
+echo "=== Benchmark Complete ==="
+echo "Session Dir: $SESSION_DIR"
+echo ""
+
+# Show run-log stats
+if [ -f "$SESSION_DIR/run-log.jsonl" ]; then
+  echo "--- Run Log Event Summary ---"
+  echo "Total events: $(wc -l < "$SESSION_DIR/run-log.jsonl")"
+  echo ""
+  echo "Events by type:"
+  cat "$SESSION_DIR/run-log.jsonl" | python3 -c "
+import sys, json
+from collections import Counter
+events = Counter()
+for line in sys.stdin:
+    try:
+        obj = json.loads(line.strip())
+        events[obj.get('event', 'unknown')] += 1
+    except:
+        pass
+for event, count in sorted(events.items()):
+    print(f'  {event}: {count}')
+" 2>/dev/null || echo "  (python3 not available for analysis)"
+  echo ""
+
+  echo "--- Compaction Events ---"
+  cat "$SESSION_DIR/run-log.jsonl" | python3 -c "
+import sys, json
+for line in sys.stdin:
+    try:
+        obj = json.loads(line.strip())
+        event = obj.get('event', '')
+        if 'compact' in event or 'overflow' in event or 'pruning' in event:
+            print(json.dumps(obj, indent=2))
+    except:
+        pass
+" 2>/dev/null || echo "  (python3 not available for analysis)"
+fi
+
+echo ""
+echo "=== Full run-log path: $SESSION_DIR/run-log.jsonl ==="
+echo "=== Session file path: $SESSION_DIR/session.jsonl ==="