vault put to 1Password stores empty password field

Description

swamp vault put reports success when storing a secret in a 1Password-backed vault, but the password field in the 1Password item is always empty afterward.

Steps to Reproduce

1. Create a 1Password-backed vault:

   swamp vault create 1password honeycomb --json

2. Store a secret via piped stdin:

   echo "my-secret-value" | swamp vault put honeycomb INGEST_KEY --json

3. swamp reports success:

   {
     "vaultName": "honeycomb",
     "secretKey": "INGEST_KEY",
     "vaultType": "1password",
     "overwritten": true,
     "timestamp": "2026-03-10T19:11:12.959Z"
   }

4. Verify the stored value via op CLI:

   op item get INGEST_KEY --vault swamp --fields password

   → Returns empty string (0 bytes)

5. Confirm the item exists but has no value:

   op item get INGEST_KEY --vault swamp --format json

   → Shows password field with empty value

Expected Behavior

The secret value piped to swamp vault put should be stored in the 1Password item's password field and retrievable via op item get.

Actual Behavior

The 1Password item is created/updated, but the password field is always empty. swamp vault put returns a success response regardless.

Repeated swamp vault put calls (including with overwritten: true) all result in the same empty password field.

Environment

• swamp version: 20260309.181646.0-sha.6cbf8466
• OS: macOS (Darwin 25.3.0, aarch64)
• Shell: zsh
• 1Password CLI: op v2.x (authenticated, working for other operations)
• Vault config: type=1password, op_vault=swamp

Additional Context

• swamp vault list-keys honeycomb correctly shows the key name INGEST_KEY
• The item appears in 1Password with the correct title but empty password
• Direct op item edit with the same value works correctly
• This was reproduced with both fresh items and overwriting existing items