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>

tests/integration/llm/test_claude_code_live.py

@@ -0,0 +1,28 @@
+"""Live integration test for ClaudeCodeAdapter.
+
+Skipped unless the ``claude`` CLI is available on PATH.
+"""
+
+import shutil
+
+import pytest
+
+from markitect.llm.claude_code import ClaudeCodeAdapter
+from markitect.prompts.execution.models import RunConfig, LLMResponse
+
+
+pytestmark = pytest.mark.skipif(
+    shutil.which("claude") is None,
+    reason="claude CLI not found on PATH",
+)
+
+
+class TestClaudeCodeLive:
+    def test_simple_completion(self):
+        adapter = ClaudeCodeAdapter()
+        config = RunConfig(timeout_seconds=60, max_tokens=50)
+        resp = adapter.execute_prompt("Reply with exactly: PONG", config)
+
+        assert isinstance(resp, LLMResponse)
+        assert len(resp.content.strip()) > 0
+        assert resp.metadata["provider"] == "claude-code"

tests/integration/llm/test_openrouter_live.py

@@ -0,0 +1,40 @@
+"""Live integration test for OpenRouterAdapter.
+
+Skipped unless an API key is available (env var or project key file).
+"""
+
+import os
+
+import pytest
+
+from markitect.llm.openrouter import OpenRouterAdapter
+from markitect.llm.config import resolve_api_key, find_project_root
+from markitect.prompts.execution.models import RunConfig, LLMResponse
+
+
+def _get_api_key():
+    root = find_project_root()
+    paths = [root / "apikey-openrouter.txt"] if root else []
+    return resolve_api_key(env_var="OPENROUTER_API_KEY", key_file_paths=paths)
+
+
+pytestmark = pytest.mark.skipif(
+    _get_api_key() is None,
+    reason="No OpenRouter API key available",
+)
+
+
+class TestOpenRouterLive:
+    def test_simple_completion(self):
+        adapter = OpenRouterAdapter(
+            model="anthropic/claude-sonnet-4",
+            api_key=_get_api_key(),
+        )
+        config = RunConfig(temperature=0.0, max_tokens=50)
+        resp = adapter.execute_prompt("Reply with exactly: PONG", config)
+
+        assert isinstance(resp, LLMResponse)
+        assert len(resp.content) > 0
+        assert resp.usage["total_tokens"] > 0
+        assert resp.finish_reason in ("stop", "length")
+        assert resp.metadata["provider"] == "openrouter"