Schema, first migration, atomic counter helpers

All tables in one linear migration, including later epics' tables, so migration order stays clean. Counter mutations are atomic SQL, never read-modify-write.

• Tables: profile (singleton), socials, experience, projects, skills, education, articles, currently (freeform label - Listening to / Playing / Reading / Watching - title, subtitle, url, imageUrl, sort; fully manual incl. music), guestbookEntries (approved NOT NULL default false, stamp, no visitorId), counters (key/value: hits)
• Atomic increment helper: UPDATE counters SET value = value + 1 ... RETURNING
• Serial DB test proves concurrent increments lose nothing