Add armonia workspace setup scripts (bootstrap + migration)

[aarontrowbridge]

Every user — Harmoniqs dev or external contributor — should get the same canonical workspace layout with one command.

Acceptance Criteria

• tools/bootstrap-armonia.sh — fresh-machine setup: creates ~/armonia/{repos/{packages,demos},data/{env,problems,runs,vaults}}, clones canonical public repos by tier (--minimal / --standard / --full), idempotent
• tools/migrate-to-armonia.sh — updated for the three-bucket repos layout (packages/, demos/, flat); still idempotent
• Both scripts safe to re-run; curl-able raw from GitHub for users who have not cloned anything yet