Fix reviewer guidelines: Require test coverage for new functionality

## Problem Reviewer approved #139 (comment creation UI) without requiring any test coverage. **Reviewer's incorrect claim:** "This project does not have controller specs for web UI controllers" **Reality:** Project HAS 8 feature specs in `/rails/spec/features/`: - `ticket_workflow_spec.rb` - relevant pattern for ticket-related flows - `kanban_board_spec.rb` - `sessions_page_spec.rb` - `approvals_spec.rb` - `dashboard_spec.rb` - `debug_dashboard_spec.rb` - `multi_terminal_page_spec.rb` - `terminal_page_spec.rb` ## Root Cause Reviewer guidelines are too lenient. New functionality should require appropriate test coverage before approval. ## Solution Update reviewer guidelines/prompts to enforce test requirements: 1. **Check for existing test patterns** before claiming "no tests in this area" 2. **Require tests for new functionality** - controller tests, request specs, or feature specs as appropriate 3. **Verify acceptance criteria** are covered by tests 4. **Reject without tests** unless there's a documented exception ## Specific Changes - Update reviewer system prompt to be stricter about test coverage - Require reviewer to search for existing spec patterns before skipping tests - Add test coverage checklist to review template ## Acceptance Criteria - Reviewer checks for existing spec patterns before claiming "no tests" - New functionality requires appropriate test coverage - Feature specs follow existing patterns (e.g., ticket_workflow_spec.rb) - Clear guidance on when each test type is appropriate