v0.2.0 — VibePulse only

What changed

One app. VibePulse is now the only app in this repository, and the screen
boots into it. The maintainer's other screens moved to their own repos and are
compiled in only if you happen to have them checked out. A fresh clone builds
exactly one thing.

Corrections. The README described a "5-hour session" page that does not
exist — the firmware builds six: Claude heaviest-model week, Claude all-models
week, Codex week, burn rate, and a Max Tracker per provider. The privacy
section was too narrow: the screen also receives coarse status (project name,
model, effort), and a lost screen carries your Mac's LAN hostname alongside
your WiFi credentials.

Setup. secrets.h.example ships the VibePulse URLs active with a
placeholder instead of commented out — an undefined URL compiles the fetch out
entirely and leaves a screen that boots happily and shows dashes forever. New
docs/agent-setup.md is a runbook for coding agents: a verification after
every step, and a symptom→fix table.

Build. Companion apps resolve during ESP-IDF early expansion and their
paths are cache variables, so a present companion is never silently dropped.
The host gate links libm and checks fread returns, so all 307 tests — SDL
landmark captures included — now run headless on Linux as well as macOS.

Upgrading

Git history was rewritten in this cycle. An existing clone will not
fast-forward: re-clone, or git fetch origin && git reset --hard origin/main.

To update a board: pull and reflash. Flash in download mode with the panel
dark, and run the screen from its own power supply.