aih-fixture-mixedlisted

## Task Synthetic SKILL exercising all 3 step formats simultaneously. ### Step 1: H3-colon format This step uses the H3 colon format (aih-feature style). ### Step 1.5: H3-sub-step format Sub-step using the H3 decimal format. ## Step 2 — H2-step format This step uses the H2 dash format (aih-milestone style). ### 3. Numbered H3 format This step uses the numbered H3 format (aih-bugfix style). ## Guardrails These guardrails are excluded from step counting. ## Autonomy This section is excluded from step counting.