docs: retire cron, record MQTT/discovery/gemma4 decisions

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

CONTEXT.md

@@ -7,7 +7,7 @@ Fetches unread articles from FreshRSS, selects and summarizes them via Ollama, t
 Forked from `Seth/PrinterAutomation` on Gitea.
 
 ## Components
-- `pos_briefing.py` — Main script. Run directly or via cron.
+- `pos_briefing.py` — Main script. Run directly or via the MQTT bridge (Google Home button).
 - `config.json` — Credentials and endpoints (not committed).
 - `config.example.json` — Template for config.json.
 
@@ -47,11 +47,12 @@ Forked from `Seth/PrinterAutomation` on Gitea.
 - **Uptime Kuma:** CT 147 — queried via `pct exec 147` (requires Proxmox host).
 - **This script runs on:** steel141 (`192.168.0.141`). Previously CT 166 (retired).
 
-## Cron
-Runs daily at 04:30 via crontab on steel141:
-```
-30 4 * * * python3 /root/bin/POS-Automation/pos_briefing.py >> /var/log/pos_briefing.log 2>&1
-```
+## Trigger
+On-demand only — **no cron**. Google Home button → HA `script.print_daily_briefing`
+→ MQTT `posbriefing/button/press` on broker CT 301 (192.168.0.154) →
+`pos-briefing-mqtt.service` on steel141 (systemd, `User=claude`) → `pos_briefing.py`
+→ printer discovered by MAC → ESC/POS over TCP. See `docs/ha-setup.md` and
+`docs/superpowers/specs/2026-06-07-ha-google-home-trigger-design.md`.
 
 ## Setup
 ```bash

DECISIONS.md

@@ -0,0 +1,35 @@
+# POS-Automation — Decisions
+
+Format: `YYYY-MM-DD: <decision> — <why>`
+
+- **2026-06-07: On-demand trigger via MQTT bridge (lgtv pattern), not cron.** Seth
+  wants a Google Home button, not a scheduled print. Bridge `pos-briefing-mqtt.service`
+  (systemd, `User=claude`) on steel141 subscribes to `posbriefing/button/press` on
+  broker CT 301 (192.168.0.154); HA exposes a `script` to Google as a Scene (button).
+  The earlier "schedule 4:58am/3pm" was never a real cron job — that commit only
+  edited SESSION.md.
+- **2026-06-07: Printer discovered by MAC `50:57:9c:eb:0f:07`, not a fixed IP.** The
+  TM-m30's IP changes on every reboot (router DHCP, no reservation). Cache last IP
+  (`~/.cache/pos-briefing/last_ip`), verify by MAC + port, sweep the /24 on a miss.
+  A router DHCP reservation would make this belt-and-suspenders but isn't required.
+- **2026-06-07: Summaries on `gemma4:26b`; story selection stays on a fast model.**
+  Seth asked to switch summaries to gemma4. gemma4:26b under `format:json` ignores
+  the bare-array instruction and emits a reasoning object (`{"thought": ...}`), which
+  broke Phase-1 selection. Selection now uses `ollama_select_model` (default
+  `qwen2.5:1.5b`); summaries use `ollama_model` = `gemma4:26b`. Also better latency
+  for an interactive button.
+- **2026-06-07: yfinance installed on steel141** via `pip --user --break-system-packages`
+  (PEP 668). It was missing after the CT 166 → steel141 migration — the original
+  "not firing" had two causes: no cron ever installed + this missing dependency.
+- **2026-06-07: paho-mqtt v1 callbacks (`CallbackAPIVersion.VERSION1`).** paho 2.1.0
+  is installed for `claude`; matches the working lgtv bridge. One-time deprecation
+  warning at startup is harmless.
+
+## Deferred / Rejected
+- **Print latency (~1–2 min/press):** gemma4:26b summarization (+ yfinance) dominates.
+  Acceptable for v1; the button returns immediately and `posbriefing/status` tracks
+  progress. Optimize later (model keep-alive, fewer/shorter summaries) if it annoys.
+- **Router DHCP reservation for the printer:** Seth's router action; MAC discovery
+  makes it optional. Add if convenient to drop the sweep fallback.
+- **zfs/reddit/grafana dashboard fields return None on steel141** (not the tank/ZFS
+  host; `cannot open 'tank'`). Out of scope for the trigger work — track separately.