feat: implement three-tier model strategy with Opus 4.5 (#139)

* feat: implement three-tier model strategy with Opus 4.5

This implements a strategic model selection approach based on agent
complexity and use case, addressing Issue #136.

Three-Tier Strategy:
- Tier 1 (opus): 17 critical agents for architecture, security, code review
- Tier 2 (inherit): 21 complex agents where users choose their model
- Tier 3 (sonnet): 63 routine development agents (unchanged)
- Tier 4 (haiku): 47 fast operational agents (unchanged)

Why Opus 4.5 for Tier 1:
- 80.9% on SWE-bench (industry-leading for code)
- 65% fewer tokens for long-horizon tasks
- Superior reasoning for architectural decisions

Changes:
- Update architect-review, cloud-architect, kubernetes-architect,
  database-architect, security-auditor, code-reviewer to opus
- Update backend-architect, performance-engineer, ai-engineer,
  prompt-engineer, ml-engineer, mlops-engineer, data-scientist,
  blockchain-developer, quant-analyst, risk-manager, sql-pro,
  database-optimizer to inherit
- Update README with three-tier model documentation

Relates to #136

* feat: comprehensive model tier redistribution for Opus 4.5

This commit implements a strategic rebalancing of agent model assignments,
significantly increasing the use of Opus 4.5 for critical coding tasks while
ensuring Sonnet is used more than Haiku for support tasks.

Final Distribution (153 total agent files):
- Tier 1 Opus: 42 agents (27.5%) - All production coding + critical architecture
- Tier 2 Inherit: 42 agents (27.5%) - Complex tasks, user-choosable
- Tier 3 Sonnet: 38 agents (24.8%) - Support tasks needing intelligence
- Tier 4 Haiku: 31 agents (20.3%) - Simple operational tasks

Key Changes:

Tier 1 (Opus) - Production Coding + Critical Review:
- ALL code-reviewers (6 total): Ensures highest quality code review across
  all contexts (comprehensive, git PR, code docs, codebase cleanup, refactoring, TDD)
- All major language pros (7): python, golang, rust, typescript, cpp, java, c
- Framework specialists (6): django (2), fastapi (2), graphql-architect (2)
- Complex specialists (6): terraform-specialist (3), tdd-orchestrator (2), data-engineer
- Blockchain: blockchain-developer (smart contracts are critical)
- Game dev (2): unity-developer, minecraft-bukkit-pro
- Architecture (existing): architect-review, cloud-architect, kubernetes-architect,
  hybrid-cloud-architect, database-architect, security-auditor

Tier 2 (Inherit) - User Flexibility:
- Secondary languages (6): javascript, scala, csharp, ruby, php, elixir
- All frontend/mobile (8): frontend-developer (4), mobile-developer (2),
  flutter-expert, ios-developer
- Specialized (6): observability-engineer (2), temporal-python-pro,
  arm-cortex-expert, context-manager (2), database-optimizer (2)
- AI/ML, backend-architect, performance-engineer, quant/risk (existing)

Tier 3 (Sonnet) - Intelligent Support:
- Documentation (4): docs-architect (2), tutorial-engineer (2)
- Testing (2): test-automator (2)
- Developer experience (3): dx-optimizer (2), business-analyst
- Modernization (4): legacy-modernizer (3), database-admin
- Other support agents (existing)

Tier 4 (Haiku) - Simple Operations:
- SEO/Marketing (10): All SEO agents, content, search
- Deployment (4): deployment-engineer (4 instances)
- Debugging (5): debugger (2), error-detective (3)
- DevOps (3): devops-troubleshooter (3)
- Other simple operational tasks

Rationale:
- Opus 4.5 achieves 80.9% on SWE-bench with 65% fewer tokens on complex tasks
- Production code deserves the best model: all language pros now on Opus
- All code review uses Opus for maximum quality and security
- Sonnet > Haiku (38 vs 31) ensures better intelligence for support tasks
- Inherit tier gives users cost control for frontend, mobile, and specialized tasks

Related: #136, #132

* feat: upgrade final 13 agents from Haiku to Sonnet

Based on research into Haiku 4.5 vs Sonnet 4.5 capabilities, upgraded
agents requiring deep analytical intelligence from Haiku to Sonnet.

Research Findings:
- Haiku 4.5: 73.3% SWE-bench, 3-5x faster, 1/3 cost, sub-200ms responses
- Best for Haiku: Real-time apps, data extraction, templates, high-volume ops
- Best for Sonnet: Complex reasoning, root cause analysis, strategic planning

Agents Upgraded (13 total):
- Debugging (5): debugger (2), error-detective (3) - Complex root cause analysis
- DevOps (3): devops-troubleshooter (3) - System diagnostics & troubleshooting
- Network (2): network-engineer (2) - Complex network analysis & optimization
- API Documentation (2): api-documenter (2) - Deep API understanding required
- Payments (1): payment-integration - Critical financial integration

Final Distribution (153 total):
- Tier 1 Opus: 42 agents (27.5%) - Production coding + critical architecture
- Tier 2 Inherit: 42 agents (27.5%) - Complex tasks, user-choosable
- Tier 3 Sonnet: 51 agents (33.3%) - Support tasks needing intelligence
- Tier 4 Haiku: 18 agents (11.8%) - Fast operational tasks only

Haiku Now Reserved For:
- SEO/Marketing (8): Pattern matching, data extraction, content templates
- Deployment (4): Operational execution tasks
- Simple Docs (3): reference-builder, mermaid-expert, c4-code
- Sales/Support (2): High-volume, template-based interactions
- Search (1): Knowledge retrieval

Sonnet > Haiku as requested (51 vs 18)

Sources:
- https://www.creolestudios.com/claude-haiku-4-5-vs-sonnet-4-5-comparison/
- https://www.anthropic.com/news/claude-haiku-4-5
- https://caylent.com/blog/claude-haiku-4-5-deep-dive-cost-capabilities-and-the-multi-agent-opportunity

Related: #136

* docs: add cost considerations and clarify inherit behavior

Addresses PR feedback:
- Added comprehensive cost comparison for all model tiers
- Documented how 'inherit' model works (uses session default, falls back to Sonnet)
- Explained cost optimization strategies
- Clarified when Opus token efficiency offsets higher rate

This helps users make informed decisions about model selection and cost control.

plugins/python-development/agents/django-pro.md

@@ -1,7 +1,7 @@
 ---
 name: django-pro
 description: Master Django 5.x with async views, DRF, Celery, and Django Channels. Build scalable web applications with proper architecture, testing, and deployment. Use PROACTIVELY for Django development, ORM optimization, or complex Django patterns.
-model: sonnet
+model: opus
 ---
 
 You are a Django expert specializing in Django 5.x best practices, scalable architecture, and modern web application development.

plugins/python-development/agents/fastapi-pro.md

@@ -1,7 +1,7 @@
 ---
 name: fastapi-pro
 description: Build high-performance async APIs with FastAPI, SQLAlchemy 2.0, and Pydantic V2. Master microservices, WebSockets, and modern Python async patterns. Use PROACTIVELY for FastAPI development, async optimization, or API architecture.
-model: sonnet
+model: opus
 ---
 
 You are a FastAPI expert specializing in high-performance, async-first API development with modern Python patterns.

plugins/python-development/agents/python-pro.md

@@ -1,7 +1,7 @@
 ---
 name: python-pro
 description: Master Python 3.12+ with modern features, async programming, performance optimization, and production-ready practices. Expert in the latest Python ecosystem including uv, ruff, pydantic, and FastAPI. Use PROACTIVELY for Python development, optimization, or advanced Python patterns.
-model: sonnet
+model: opus
 ---
 
 You are a Python expert specializing in modern Python 3.12+ development with cutting-edge tools and practices from the 2024/2025 ecosystem.