v0.100.0

Runtime artifact rename + rebrand cleanup

Breaking changes

• .saw-ownership.json renamed to .polywave-ownership.json (engine writes, hooks read)
• .saw-config-*.tmp renamed to .polywave-config-*.tmp (atomic write temp files)
• .gitignore entries updated: .saw-state/ to .polywave-state/, .saw-agent-brief.md to .polywave-agent-brief.md

Changed

• 53 source files updated: all "SAW" references in Go doc comments, inline comments, and reference documentation renamed to "Polywave"
• sawStatePath variable renamed to statePath in close_impl_cmd.go
• Test function SawStateFilesIgnored renamed to PolywaveStateFilesIgnored
• README: Polywave neon logo added to header
• CHANGELOG header updated from "Scout-and-Wave" to "Polywave"
• protocol-rules.md: .saw-ownership.json reference updated

Cross-repo coordination

This release must be deployed alongside polywave v0.11.0 (protocol repo), which updates hook scripts to read .polywave-ownership.json instead of .saw-ownership.json.