v0.2.0 — Clone-and-go onboarding

Clone-and-go onboarding

Ties together Tars's existing setup automation, MCP companion docs, persona
prompt, and routines into one ordered Day-0 runbook — a fresh clone can now be
taken end to end (server → MCPs → persona → seeded brain → scheduled routines)
without tribal knowledge.

• New: docs/onboarding.md — the Day-0 runbook.
• New: docs/routines/bootstrap.md — a
  one-time, wide-window sweep across every connected source that seeds the
  brain before Dream/Briefing (which only reconcile new activity) have
  anything to work with.
• Dream and Briefing routine docs now include concrete "Instantiating on
  Claude Code" steps (the /schedule skill + a personal drop-in file
  pattern), replacing the previous "copy this into a scheduled task."
• docs/tars-system-prompt.md now specifies the persona goes in the global
  ~/.claude/CLAUDE.md, not the project one.
• README and CLAUDE.md point new users/sessions at the runbook.

Docs-only release — no code or schema changes.