feat(llm): add LLM integration module with OpenRouter and Claude Code adapters

Implements markitect/llm/ package with concrete LLMAdapter implementations:
- OpenRouterAdapter: HTTP via urllib with retry/backoff on 429/5xx
- ClaudeCodeAdapter: subprocess-based Claude CLI with stdin piping
- Factory pattern: create_adapter("openrouter") or create_adapter("claude-code")
- API key resolution chain: constructor > env var > project-root key file
- 42 unit tests, 2 integration tests (gated on API key / CLI availability)

Also adds the infospace-with-history example with Wealth of Nations VSM
analysis pipeline, templates, schemas, source chapters, and processed
output for chapters 1-2. process_chapters.py now supports --provider
and --model flags for automatic LLM-driven processing.

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

roadmap/260210-llm-integration/WORKPLAN.md

@@ -0,0 +1,59 @@
+# LLM Integration Module — Work Plan
+
+**Date**: 2026-02-10
+**Status**: Implemented
+
+## Overview
+
+Added `markitect/llm/` package providing concrete `LLMAdapter` implementations
+so any MarkiTect component can call an LLM through OpenRouter (HTTP) or
+Claude Code CLI (subprocess).
+
+## Module Layout
+
+```
+markitect/llm/
+├── __init__.py           # Public API
+├── exceptions.py         # LLMError hierarchy (extends MarkitectError)
+├── config.py             # LLMConfig dataclass, API key resolution
+├── _http.py              # Sync HTTP helper (urllib.request)
+├── _token_estimator.py   # Rough token counting for CLI backend
+├── openrouter.py         # OpenRouterAdapter(LLMAdapter)
+├── claude_code.py        # ClaudeCodeAdapter(LLMAdapter)
+└── factory.py            # create_adapter() factory function
+```
+
+## Design Decisions
+
+- Implements existing `LLMAdapter` ABC — no interface changes
+- No new pip dependencies (stdlib only: urllib.request, subprocess)
+- API key resolution: constructor arg > env var > project-root key file
+- Factory pattern: `create_adapter("openrouter")` or `create_adapter("claude-code")`
+
+## Testing
+
+- 42 unit tests in `tests/unit/llm/` (all mocked, no network)
+- Integration tests in `tests/integration/llm/` (skip if no API key / CLI)
+
+## Example Integration
+
+`examples/infospace-with-history/process_chapters.py` accepts `--provider`
+and `--model` CLI args. When a provider is specified, each pipeline stage
+auto-generates output via the LLM adapter instead of waiting for manual input.
+
+## Verification
+
+```bash
+# Unit tests
+pytest tests/unit/llm/ -v
+
+# Integration (OpenRouter)
+OPENROUTER_API_KEY=$(cat apikey-openrouter.txt) pytest tests/integration/llm/test_openrouter_live.py -v
+
+# Integration (Claude Code CLI)
+pytest tests/integration/llm/test_claude_code_live.py -v
+
+# End-to-end
+python examples/infospace-with-history/process_chapters.py \
+  --chapter book-1-chapter-03 --provider claude-code --no-commit
+```