Holo

Holo is an experimental native macOS utility that turns the desk immediately around a MacBook into four assignable tap zones. It listens through the selected Mac microphone, extracts acoustic features from short impulse windows, classifies the zone locally, and runs the action assigned to that zone.

The topology is intentionally four broad zones:

                  Display side
Left Rear      ┌─────────────┐      Right Rear
               │   MacBook   │
Left Front     └─────────────┘      Right Front
                  Trackpad side

Holo is a research prototype. Automated DSP tests pass, but useful accuracy still has to be measured on each real MacBook, desk, room, and laptop position. No physical accuracy claim is made without a saved 60-tap evaluation from that setup.

The requirement-by-requirement evidence ledger is in ACCEPTANCE.md.

What is implemented

• Four fixed zones: rear and front zones on each side of the MacBook.
• Explicitly armed calibration: ten accepted examples spread across each zone, 40 total, with clear retry guidance for weak, noisy, or clipped taps.
• A calibration-consistency check that identifies and can redo the weakest zone before saving.
• Adaptive streaming onset detection, sustained-sound rejection, and fixed 90 ms analysis windows.
• Passive tap acoustics, an optional active acoustic probe, and a hybrid mode.
• Robust feature normalization, a regularized linear zone model backed by nearest-example novelty checks, ambiguity rejection, out-of-distribution rejection, and optional negative examples.
• Per-profile actions: visual only, play a sound, copy or speak text, open a website, run a Shortcut, open an application or item, execute a shell command, or capture a screenshot. New zones default to visual-only until the user assigns a side effect.
• Guided 60-tap held-out evaluation with per-zone accuracy, latency, rejected-tap counts, and a confusion matrix.
• Saved evaluation history is restored after relaunch and scoped to the desk profile that produced it.
• Signal diagnostics, labeled feature capture, approach comparison, JSON/CSV reports, and opt-in raw debug WAV capture.
• Sandboxed, local persistence. Raw audio is discarded by default.
• Core Audio route validation requires the built-in microphone for every mode and the built-in speakers for Active or Hybrid sensing.

Requiremen