issues create / issues update only accept one relation flag at a time

[iamfj]

Description

The issues create and issues update commands only allow a single relation flag per invocation. Passing multiple relation flags (e.g. --blocks and --relates-to) results in an error. In practice, issues often have multiple relations that should be set at creation time.

Steps to Reproduce

linearis issues create "Fix schema mismatch" \
  --team data \
  --blocks DAT-1034 \
  --relates-to DAT-913

Expected Behavior

The issue is created with both relations: blocks DAT-1034 and relates to DAT-913.

Actual Behavior

{
  "error": "Only one relation flag can be used at a time"
}

Workaround

Create the issue with one relation, then use issues update to add the second:

linearis issues create "Fix schema mismatch" --team data --blocks DAT-1034
linearis issues update DAT-1047 --relates-to DAT-913

Environment

• Branch: next
• Affects: issues create and issues update