fix(relay): register V010/V011 migrations; fix retry test precondition; add share assertions
Blocking fixes from second review pass:
- Register V010 (recovery_share) and V011 (pending_share_{1,2,3}) in migration runner;
missing registration meant all route tests hit 500 (column not found) in CI
- Fix retry test broken precondition: pre-store all three shares alongside pending_did so
the retry branch doesn't 500 on NULL share columns; assert returned shares match
pre-stored values, proving idempotent reuse rather than fresh generation
- Add shamir_share_1 / shamir_share_3 assertions to happy-path test (presence, 52-char,
BASE32 alphabet); add recovery_share DB assertion (NOT NULL, 52-char, BASE32 alphabet)
Minor fixes:
- Fix doc comment: shamirShare1/3 → shamir_share_1/3 (actual wire field names)
- Add comment in generate_recovery_shares noting base32 String outputs are not zeroized
- Add console.error in ShamirBackupScreen clipboard catch for debug visibility