fix: add try-finally to executeRecovery to guarantee state cleanup

[0x-SquidSol]

Summary

• If wallet recovery failed mid-execution (network error, invalid key, etc.), cleanup code never ran
• abortController remained stale, currentStatus stuck in 'executing', and loaded keypairs with private key material stayed in memory
• Wrapped recovery phases in try-finally to guarantee cleanup: status reset to idle, abortController nulled, and keys securely wiped via clearLoadedWallets()

Test plan

• Run a recovery that succeeds — verify cleanup and status reset
• Simulate a recovery failure — verify state resets to idle and keys are cleared
• Run pnpm run typecheck — passes clean
• Run pnpm run test — all wallet tests pass (19/19)

[nullxnothing]

Closed as superseded by #75, which reapplies the corrected security hardening on top of current main. This avoids merging stale/conflicted branches and preserves the fixes with passing CI/CodeQL.