feat: Update to production model stack and fix remaining inconsistencies

## Model Stack Updates (User's Actual Models)

Updated all documentation to reflect production models:
- Claude Opus 4.5 (primary reasoning)
- GPT 5.1 Codex max (code generation specialist)
- Gemini 3 Pro/Flash (multimodal, fast inference)
- Qwen3-235B (cost-effective, self-hostable)
- DeepSeek V3.2 (self-hosted, open weights)

### Files Updated:
- ADR-004: Full model groups, failover chains, cost tables
- ADR-007: Code example with correct model identifiers
- ADR-012: Cost tracking with new model prices
- ARCHITECTURE.md: Model groups, failover diagram
- IMPLEMENTATION_ROADMAP.md: External services list

## Architecture Diagram Updates

- Added LangGraph Runtime to orchestration layer
- Added technology labels (Type-Instance, transitions)

## Self-Hostability Table Expanded

Added entries for:
- LangGraph (MIT)
- transitions (MIT)
- DeepSeek V3.2 (MIT)
- Qwen3-235B (Apache 2.0)

## Metric Alignments

- Response time: Split into API (<200ms) and Agent (<10s/<60s)
- Cost per project: Adjusted to $100/sprint for Opus 4.5 pricing
- Added concurrent projects (10+) and agents (50+) metrics

## Infrastructure Updates

- Celery workers: 4-8 instances (was 2-4) across 4 queues
- MCP servers: Clarified Phase 2 + Phase 5 deployment
- Sync interval: Clarified 60s fallback + 15min reconciliation

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docs/architecture/IMPLEMENTATION_ROADMAP.md

@@ -295,10 +295,13 @@ This roadmap outlines the phased implementation approach for Syndarix, prioritiz
 | Metric | Target | Measurement |
 |--------|--------|-------------|
 | Agent task success rate | >90% | Completed tasks / total tasks |
-| Response time (P95) | <2s | API latency |
-| Cost per project | <$50/sprint | LLM + compute costs |
+| API response time (P95) | <200ms | Pure API latency (per NFR-101) |
+| Agent response time | <10s simple, <60s code | End-to-end including LLM (per NFR-103) |
+| Cost per project | <$100/sprint | LLM + compute costs (with Opus 4.5 pricing) |
 | Time to first commit | <1 hour | From requirements to PR |
 | Client satisfaction | >4/5 | Post-sprint survey |
+| Concurrent projects | 10+ | Active projects in parallel |
+| Concurrent agents | 50+ | Agent instances running |
 
 ---
 
@@ -328,15 +331,17 @@ Foundation    Core Platform   MCP Integration  Agent Orch    Workflows     Advan
 ### Infrastructure
 - PostgreSQL (managed or self-hosted)
 - Redis (managed or self-hosted)
-- Celery workers (2-4 instances)
-- MCP servers (7 containers)
+- Celery workers (4-8 instances across 4 queues: agent, git, sync, cicd)
+- MCP servers (7 containers, deployed in Phase 2 + Phase 5)
 - API server (2+ instances)
 - Frontend (static hosting or SSR)
 
 ### External Services
-- Anthropic API (primary LLM)
-- OpenAI API (fallback)
-- Ollama (local models, optional)
+- Anthropic API (Claude Opus 4.5 - primary reasoning)
+- OpenAI API (GPT 5.1 Codex max - code generation)
+- Google API (Gemini 3 Pro/Flash - multimodal, fast)
+- Alibaba API (Qwen3-235B - cost-effective, or self-host)
+- DeepSeek V3.2 (self-hosted, open weights)
 - Gitea/GitHub/GitLab (issue tracking)
 
 ---