fix: power-steering incorrectly blocks Q&A/PM sessions with dev checks (#2914)

[rysweet]

Summary

• Remove INVESTIGATION from workflow_invocation, next_steps, and documentation_updates applicable_session_types — these are dev-specific checks that produce false positives on investigation/PM sessions
• Add new skill_invocation check: if a <command-name> tag exists in the transcript (user ran a slash command), verify the Skill tool was called for that skill

Problem

During a /pm-architect session (pure PM prioritization), power-steering blocked the session 4-5 times with irrelevant checks like workflow_invocation (demanded dev-orchestrator), next_steps (flagged the prioritized backlog as "remaining work"), and documentation_updates.

Root cause

Three INVESTIGATION blocker checks were designed for development workflows and don't apply to PM/research sessions:

• workflow_invocation — demands Skill/Read for workflow file, but PM skills don't need dev-orchestrator
• next_steps — flags project backlogs as incomplete work when the backlog IS the deliverable
• documentation_updates — demands doc updates for sessions that don't change code

Test plan

• 49/49 session classification tests pass (1 pre-existing failure excluded)
• Pre-existing test failures confirmed on main branch (not introduced by this PR)
• Manual: Run /pm-architect and verify power-steering doesn't block with dev checks
• Manual: Run /dev and verify skill_invocation check passes when dev-orchestrator is called

🤖 Generated with Claude Code

[github-actions]

🤖 Auto-fixed version bump

The version in pyproject.toml has been automatically bumped to the next patch version.

If you need a minor or major version bump instead, please update pyproject.toml manually and push the change.

[rysweet]

Closing: merge conflicts with the power_steering_checker package refactor (#2910). The considerations.yaml and checks_workflow.py changes will be reimplemented in a fresh PR against the current package structure. The skill_invocation check is valuable and will be preserved.