Auto-assign contributors to help wanted issues via /assign command

[rtibbles]

❌ This issue is not open for contribution. Visit Contributing guidelines to learn about the contributing process and how to find suitable issues.

Current behavior

When a contributor comments on an unassigned help wanted issue, a Slack notification is sent to #support-dev. A team member then needs to manually review and assign the contributor to the issue. This creates delays and requires manual intervention for every assignment.

Desired behavior

Add a /assign slash command that allows contributors to self-assign to help wanted issues, with safeguards to prevent abuse.

How it works:

• The help wanted header (automatically added to issues) is updated to include instructions to comment /assign and a note about the 2-issue maximum limit
• When a contributor comments /assign on an eligible issue (labeled help wanted, currently unassigned), the bot automatically assigns them and posts a confirmation
• Contributors are limited to a maximum of 2 assigned issues at a time across all community repositories (kolibri, studio, kolibri-design-system, le-utils, .github, ricecooker)
• To prevent issue shopping (dropping issues to grab more interesting ones), issues unassigned within the last 7 days still count toward the 2-issue limit
• When a contributor is at the limit, the bot declines and lists their current assignments (and recently dropped issues with remaining cooldown days)

What stays the same:

• Existing Slack notifications for issue comments
• Existing bot replies for non-eligible issues (BOT_MESSAGE_ISSUE_NOT_OPEN, BOT_MESSAGE_ALREADY_ASSIGNED)
• All close contributor and core team handling

/assign behavior

Contributor type	Issue type	Comment	Action
Core team	Any	/assign	No action (not a contributor)
Close contributor	Any	/assign	No action (not processed)
Other	Unassigned help-wanted	/assign (under limit)	Assign user, bot confirms
Other	Unassigned help-wanted	/assign (at limit)	Bot declines, lists current + recently dropped assignments
Other	help-wanted assigned to someone else	/assign	Bot says already assigned (existing behavior)
Other	Not help-wanted	/assign	Bot says not open for contribution (existing behavior)

Value add

• Eliminates manual assignment overhead for the team - no more monitoring Slack and manually assigning contributors to issues
• Faster turnaround for contributors - they can start working immediately instead of waiting for a team member to assign them
• The 2-issue limit and 7-day cooldown enforce good contribution habits (focus on completing work, not grabbing issues)

Possible tradeoffs

• The GitHub App token needs issue write permissions (assign) in addition to the existing comment permissions - this may need to be verified/updated in consuming repositories
• The 7-day cooldown on recently unassigned issues requires querying issue timeline events across all community repos, which adds API calls
• The 2-issue limit is org-wide across all community repos - a contributor can't have e.g. 2 issues in kolibri and 1 in studio. This is intentional but worth noting for the team

Acceptance Criteria

• The help wanted issue header includes instructions to comment /assign and mentions the 2-issue limit
• Commenting /assign on an unassigned help wanted issue assigns the commenter and posts a confirmation message
• Contributors with 2+ currently assigned issues (across all community repos) are declined with a message listing their assignments
• Issues unassigned within the last 7 days count toward the 2-issue limit
• The decline message shows both current assignments and recently dropped issues with remaining cooldown days
• /assign on a non-help wanted issue or an already-assigned issue is handled by existing bot messages
• Existing Slack notification behavior is unchanged
• Documentation in docs/community-automations.md is updated