feat: add inst_019 for improved context pressure monitoring
## Problem Identified
ContextPressureMonitor reports "NORMAL" (6.7%) pressure while frequent
compaction events occur. User observed disconnect between pressure scores
and actual session sustainability.
## Root Cause
Current monitor only tracks response token generation, NOT total context
window consumption:
- ✅ Tracks: Response tokens, message counts
- ❌ Missing: Tool result sizes, system prompts, function schemas
## Example from This Session
- Reported tokens: ~50k (25% of budget)
- Actual context used: ~90k+ tokens
- instruction-history.json read twice (12k tokens)
- concurrent-session-architecture doc (large)
- Multiple bash outputs
- System prompts and reminders
Result: Compaction at "NORMAL" pressure
## inst_019 Requirements
Track total context window consumption:
- Response tokens (current)
- User messages (current)
- Tool result sizes (NEW - estimate from file reads, grep, bash)
- System overhead (NEW - ~5k tokens baseline)
- Compaction risk prediction (NEW - warn when >70% context used)
## Implementation Timeline
- Priority: MEDIUM (doesn't block current work)
- Phase: 4 or 6 (validation engine or polish phase)
- Complexity: 4-6 hours (requires instrumentation of tool calls)
## Impact
- Better compaction prediction
- Earlier handoff warnings
- More accurate pressure reporting
- Reduced unexpected session terminations
Quadrant: OPERATIONAL | Persistence: HIGH | Session: 2025-10-10-api-memory-transition
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
51f6712090