diet-guard/diet-guard-sync.service

[Unit]
Description=Diet Guard cross-device log sync (GitHub-backed)
After=network-online.target
Wants=network-online.target

[Service]
Type=oneshot
# Headless: no DISPLAY/XAUTHORITY needed, unlike diet-guard-gate.service.
# Deliberately a separate unit from the gate, not piggybacked on its tick:
# the gate is a *blocking* oneshot that holds the lock open until a meal is
# logged, so running sync on the same schedule would mean sync silently
# stalls for as long as a lock is showing.
ExecStart=/usr/bin/python -m diet_guard sync
Add cross-device log sync (Python half of Milestone 3) Pulls every other device's pushed log from GitHub-backed dumb storage, merges it with the local log, and pushes this device's own merged copy back -- the PC half of the diet-guard-app sync plan. - _sync_merge.py: pure union-by-id merge, tombstone always wins, legacy (time, desc) dedup for pre-id entries. Commutative and idempotent. - _sync_github.py: minimal GitHub Contents API client (list/get/put), distinguishing a 404 on an unused path from the repo itself being unreachable. - _sync.py: orchestration -- pull, merge, re-sign every persisted entry regardless of origin, write, rebuild the food bank, push. Re-signing unconditionally is load-bearing: an unsigned phone-origin entry would otherwise be silently dropped on the very next read once a machine holds the shared HMAC key. - _foodbank.rebuild_food_bank(): the "replay a full log into a fresh bank" entrypoint the Python side was missing (the Dart port already had its equivalent). Backs sync's bank-rebuild step. - New diet-guard-sync.service/.timer (15-minute cadence, headless, a separate unit from the gate so a held lock can't stall sync) and a new install.sh step to install them. - Created the private kuhyx/diet-guard-sync GitHub repo for storage. Incidental to this feature: adding the `sync` subcommand pushed _cli.py past the repo's 500-line cap, so `gate`'s CLI glue moved out alongside sync's into _cli_gate.py/_cli_sync.py -- same split pattern already used for the gate window logic itself, not a sync-specific design choice. 338 tests, 100% branch coverage. Verified importing and running cleanly under /usr/bin/python (the production interpreter), not just the dev venv -- the gap that caused the earlier 3-day outage. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01FU3f5KQ1GHXsbbSecfVEyF 2026-06-22 19:36:27 +02:00			`[Unit]`
			`Description=Diet Guard cross-device log sync (GitHub-backed)`
			`After=network-online.target`
			`Wants=network-online.target`

			`[Service]`
			`Type=oneshot`
			`# Headless: no DISPLAY/XAUTHORITY needed, unlike diet-guard-gate.service.`
			`# Deliberately a separate unit from the gate, not piggybacked on its tick:`
			`# the gate is a blocking oneshot that holds the lock open until a meal is`
			`# logged, so running sync on the same schedule would mean sync silently`
			`# stalls for as long as a lock is showing.`
			`ExecStart=/usr/bin/python -m diet_guard sync`