Fix wallet confirm under serve for passkey sealed approvals

[0xdewy]

Summary

• route daemon-backed bloom wallet confirm through plain IPC write instead of write_unlocked
• on daemon PermissionDenied, run the foreground Sealed Approval ceremony, write approval.json, and retry the same write
• add a socket-present CLI regression proving wallet confirm uses the VFS write lane

Checklist

• Tests added or updated for behavior changes
• Architecture docs (docs/architecture/) updated if contracts or behavior changed - N/A, this preserves the existing Sealed Approval/VFS contract and fixes the CLI route
• Sealed Approval invariants respected (no signing outside a grant or bounded capability, no PRF/grant persistence, execution from sealed bytes)
• Agent Documentation updated (crates/bloom-vfs/src/docs/agent-guidance.md and affected Petal READMEs) - N/A, no agent-facing VFS surface or Petal guidance changed

Verification

• cargo fmt
• cargo test -p bloom wallet_confirm_uses_plain_ipc_write_when_socket_exists -- --nocapture
• cargo test -p bloom-daemon passkey_write_unlocked_is_hard_disabled -- --nocapture
• cargo test -p bloom-vfs approval_challenge_is_visible_and_read_only -- --nocapture
• cargo check -p bloom
• git diff --check

Closes #90