Add writing skill suite and fanfic trend tracker scaffold

[sinfiny]

Summary

• Adds a new suite of focused writing and storytelling skills with SKILL.md contracts, agent configs, and supporting references.
• Introduces bots/, a fanfic trend-tracking starter with site adapters, crawl/extract/originalize CLI entrypoints, popularity scoring, and site catalog metadata.
• Adds a NextChapter marketing site shell plus a shared content/styling baseline for the new product direction.
• Captures supporting research and strategy notes for writing-skill partitioning and fanfiction platform trend analysis.
• Updates the repo README to reflect the implemented skill families and the remaining integration work.

Testing

• Not run (no automated checks requested in this branch summary).
• Reviewed the change set for new package manifests, CLI scaffolds, and content files added across the new skill and bot directories.
• Not run: build, lint, or end-to-end crawl/extract verification.