docs: add Session 6 competitive analysis to AMELIORATIONS.md (#382)

Added comprehensive analysis of latest features from competitors:

Claude Code:
- Skills Hot Reloading and Isolated Context (v2.2)
- Wildcard Pattern Matching for Skills
- Real-Time Thinking Blocks
- --add-dir support for CLAUDE.md

Droid (Factory.ai):
- CLI Axiom Skill (v0.49.0)
- Background Processes with /bg-process (v0.26.8)
- MCP Registry expansion (30+ servers)
- Directory-Specific Sessions
- Interleaved Thinking Support

OpenCode:
- GitHub Agent with auto-installation
- Web Interface with mDNS discovery
- MCP OAuth Management
- Stats command with filtering

Codex:
- Network Sandbox Proxy (v0.90.0)
- Collaboration Mode Beta (Plan → Execute)
- Slack Integration Native (GA)
- Codex SDK TypeScript
- Dynamic Tools Injection (v0.92.0)
- Team Config for shared configuration

Updated statistics:
- 39 critical gaps identified
- 55 important gaps identified
- 82+ useful gaps identified
- Estimated 15-18 months dev effort for critical features

Co-authored-by: Droid Agent <droid@factory.ai>

Author: echobt