Move node access log storage from PostgreSQL/SQLite to ClickHouse
(database: openflare). System startup now requires a healthy ClickHouse
connection and auto-initializes the schema. Agent heartbeat writes access
logs via batch insert; goose migration drops the legacy relational table.
Delete the old monolithic openflare-server implementation and rename
Wavelet/ to openflare-server/ to complete the migration consolidation.
Update CI workflows, agent Dockerfiles, and deployment docs for the new
layout (frontend/, docker/Dockerfile).