Add cross-links to book, agent-in-a-box, and BFL

Every piece of the product ecosystem now links to every other piece:
AgentSesh README → book + agent-in-a-box + BFL. PyPI metadata adds
Documentation and Blog URLs pointing to BFL.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: ateeples

README.md

@@ -178,6 +178,14 @@ cd agentsesh
 pip install -e .
 ```
 
+## Learn more
+
+AgentSesh measures what *Practices for Agents* describes — the behavioral patterns that determine whether AI coding sessions ship or churn. The book covers the research behind the collaboration analysis, the 84% gap, and why process grades are anti-correlated with shipping.
+
+- **[Practices for Agents](https://boldfaceline.com/book)** — the book. Free to read online, PDF+EPUB available.
+- **[agent-in-a-box](https://github.com/ateeples/agent-in-a-box)** — starter kit with brain, identity, and practices for persistent agents.
+- **[Bold Face Line](https://boldfaceline.com)** — essays on agent cognition and self-observability.
+
 ## License
 
 MIT

pyproject.toml

@@ -35,6 +35,8 @@ sesh-web = "sesh.web.server:main"
 [project.urls]
 Homepage = "https://agentsesh.com"
 Repository = "https://github.com/ateeples/agentsesh"
+Documentation = "https://boldfaceline.com/book"
+Blog = "https://boldfaceline.com"
 
 [tool.setuptools.packages.find]
 include = ["sesh*"]