[Epic 5] Controls: DDC, native & software brightness, color, audio, OSD

[aquitaine]

Epic: Controls

Per-display brightness/audio/color/input across native, DDC, and software routes — with honest verification.

Milestone: M2 · PRD: CTL-001…CTL-014

Scope

• DDC per-route probe (VCP, timing, read-back); distinguish display support from transport failure (CTL-001/013).
• Brightness via best provider (native/DDC/software/combined) with active-provider display (CTL-002/003/004).
• Volume/mute/contrast/input with verification state; normalize ranges to 0–100 (CTL-003/004/005).
• Rate-limit & coalesce writes; group sync with per-display offsets (CTL-006/007, §9.2).
• Media-key routing (main/pointer/focus/group) + custom OSD (CTL-008, CTL-009/UX-007).
• Color profile selection & protection (CTL-009); raw DDC diagnostics read-only (CTL-013).

Acceptance

• UI/API verification label always matches read-back (100% contract tests); unverifiable writes reported unverified, never success.