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>

examples/infospace-with-history/artifacts/guidelines/extraction-rules.md

@@ -0,0 +1,61 @@
+---
+id: extraction-rules
+name: extraction_rules
+artifact_type: content
+description: Guidelines for extracting economic entities from source text
+version: 1.0.0
+---
+
+# Entity Extraction Rules
+
+## What Constitutes an Entity
+
+An economic entity is a distinct concept, actor, mechanism, or institution
+that plays a functional role in Adam Smith's economic analysis. Extract
+entities at the level of specificity where they carry independent meaning.
+
+## Extraction Criteria
+
+1. **Concepts**: Abstract economic ideas (e.g., "division of labour",
+   "effectual demand", "natural price"). Extract when Smith defines,
+   explains, or argues about the concept.
+
+2. **Actors**: Economic agents with defined roles (e.g., "the labourer",
+   "the merchant", "the sovereign"). Extract when the actor performs
+   a distinct economic function.
+
+3. **Mechanisms**: Processes or dynamics that produce economic effects
+   (e.g., "accumulation of stock", "market price adjustment",
+   "foreign trade"). Extract when the mechanism is described as
+   producing specific outcomes.
+
+4. **Institutions**: Organised structures that shape economic behaviour
+   (e.g., "the corporation", "the guild", "the joint-stock company").
+   Extract when the institution's economic function is described.
+
+## Granularity Rules
+
+- Extract at the level of a single coherent concept.
+- Do NOT extract synonyms as separate entities — choose the primary term
+  Smith uses and note variations.
+- DO extract distinct aspects of a broad concept as separate entities when
+  Smith treats them independently (e.g., "wages of labour" and "profits
+  of stock" are separate from "price of commodities" even though they
+  compose it).
+- If an entity appears across multiple chapters, extract it on first
+  significant appearance and note cross-references in later chapters.
+
+## Naming Conventions
+
+- Use Smith's own terminology where possible.
+- Normalise to lowercase except for proper nouns.
+- Use the most common form Smith uses (e.g., "division of labour" not
+  "divided labour").
+
+## Quality Checks
+
+- Each entity must have a definition that would be comprehensible without
+  reading the source chapter.
+- Each entity must cite the specific book and chapter of first appearance.
+- Economic Domain must be one of: Production, Distribution, Exchange,
+  Consumption, Accumulation, Regulation, or General Theory.