v0.2.0

Stage (1b) of the MCP migration (#22): the ingest pipeline, publish paths and SQL execution move out of the skill's scripts and into slop_writer.

• New modules: errors, messages, scrape, stats, scheduled, publish, query; group gains the scan.
• The domain raises SlopWriterError/UsageError instead of printing and exiting, so typer is no longer a dependency of this package.
• Domain functions return their summary shape; rendering is the caller's job.
• The write surface stays isolated: slop_writer.publish is the only module that can post.

Breaking for anyone importing the 0.1.0 modules directly: tg._require_session/tg._resolve_peer are now require_session/resolve_peer.