[Skill Enhancement] Enforce assignee check in pull-request Pre-Flight to mitigate 30% unassigned closure rate

Problem Statement

A recent empirical audit of the last 100 closed tickets revealed that ~30% (26 out of 88) of ai-labeled, closed-as-COMPLETED tickets had no assignee at the time of closure (e.g., #11013, #11005, #10990, #10980).

While the ticket-intake skill explicitly mandates using the manage_issue_assignees tool to claim a ticket, this step is frequently skipped by the swarm under Auto Mode velocity bias. Unassigned tickets degrade accountability, disrupt the MX reward signal ("Contributions > Commits"), and pollute historical context mapping for the Native Edge Graph.

Proposed Solution

Instead of relying solely on the intake phase (which is prone to being skipped), we must implement a fail-safe mechanical check at the execution boundary.

As suggested by Operator @tobiu, we need to add a "1-liner hook" Pre-Flight check in the .agents/skills/pull-request/SKILL.md that mandates:

1. Verify Assignment: The agent must verify if they are assigned to the target ticket before committing work.
2. Assign if Missing: If the agent is not assigned, they MUST call manage_issue_assignees(action: 'add', assignees: ['@me']) BEFORE executing git commit or opening the PR.

Expected Outcome

• Total eradication of the unassigned-ticket phenomenon for agent-driven work.
• Increased accountability and a cleaner dataset for the Memory Core.
• A mechanical backstop against velocity-bias slip-ups during the intake phase.

Relevant Files

• .agents/skills/pull-request/SKILL.md
• .agents/skills/ticket-intake/SKILL.md (for reference)