docs: add README with setup, deployment, and data source research

Covers local dev, Docker deployment, env vars, data model, and
a summary of plant data sources investigated (Perenual, OpenFarm,
Trefle, Wikipedia, Google) including the commercial data opportunity.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

README.md

@@ -0,0 +1,112 @@
+# PlantDB
+
+A personal plant management web app built with Django 5, Bootstrap 5, and HTMX.
+
+Track your plants, log pruning activity, and get care info auto-filled from the Perenual species database.
+
+## Features
+
+- **Species search** — search Perenual API by name; care data (watering, sunlight, pruning months) is auto-filled into the plant form and cached locally so the API is only called once per species
+- **Plant list** — filterable by name, location, indoor/outdoor
+- **Plant detail** — shows care info, pruning status, and pruning history
+- **Pruning log** — log a pruning event with date and notes via HTMX partial update
+- **Pruning calendar** — all plants grouped by urgency: overdue, due this month, due next month, later
+- **Dashboard** — plant count, overdue pruning count, and attention list
+
+## Data model
+
+```
+Species          — cached from Perenual API (common_name, scientific_name, watering,
+                   sunlight, pruning_months, api_image_url, perenual_id)
+
+Plant            — your actual plant (name, location, is_indoor, pruning_months,
+                   photo, notes, species FK)
+
+PruningLog       — pruning events (plant FK, pruned_on, notes)
+```
+
+`Plant.pruning_months` is a JSON list of integers (1–12). It defaults to the species value but can be overridden per plant.
+
+## Tech stack
+
+| Layer | Library |
+|---|---|
+| Framework | Django 5.2 |
+| Frontend | Bootstrap 5.3 + HTMX 1.9 |
+| Image handling | Pillow |
+| HTTP client | requests |
+| Server | Gunicorn + Nginx |
+| Database | SQLite |
+
+## Local development
+
+```bash
+python -m venv .venv && source .venv/bin/activate
+pip install -r requirements.txt
+python manage.py migrate
+python manage.py runserver
+```
+
+Set `PERENUAL_API_KEY` in your environment to enable species search (free tier: 100 requests/day).
+
+Run tests:
+
+```bash
+pytest
+```
+
+## Deployment (Docker)
+
+The production stack runs as two containers: `web` (Gunicorn) behind `nginx`.
+
+```bash
+# On the host — first time
+cp .env.example .env   # fill in SECRET_KEY, PERENUAL_API_KEY, ALLOWED_HOSTS, CSRF_TRUSTED_ORIGINS
+docker compose up -d --build
+```
+
+After code changes:
+
+```bash
+# Sync files from dev machine
+rsync -av --exclude='*.pyc' --exclude='__pycache__' . dockerhost:/home/stephan/stacks/plantdb/
+
+# Rebuild
+ssh dockerhost "cd /home/stephan/stacks/plantdb && docker compose up -d --build web"
+```
+
+### Environment variables
+
+| Variable | Required | Example |
+|---|---|---|
+| `SECRET_KEY` | yes | long random string |
+| `DEBUG` | no | `False` |
+| `ALLOWED_HOSTS` | yes | `localhost,127.0.0.1,dockerhost` |
+| `CSRF_TRUSTED_ORIGINS` | yes (non-localhost) | `http://dockerhost:8083` |
+| `PERENUAL_API_KEY` | no | `sk-...` |
+
+`CSRF_TRUSTED_ORIGINS` is required when accessing the app on a non-standard port or hostname — Django 5 rejects POSTs without it.
+
+### Volumes
+
+| Volume | Purpose |
+|---|---|
+| `db` | SQLite database at `/app/data/db.sqlite3` |
+| `media` | User-uploaded plant photos |
+| `static` | Collected static files |
+
+## Plant data sources — research notes
+
+The app currently uses **Perenual** (free tier, 100 req/day) for species data. Other sources investigated:
+
+| Source | Status | Verdict |
+|---|---|---|
+| **Perenual** | Active | Best structured care data (watering, sunlight, pruning months). Free tier sufficient for personal use; each species is cached after first lookup. |
+| **OpenFarm** | Shut down April 2025 | Dead. GitHub repo is a Ruby/MongoDB app with no data dump. |
+| **Trefle** | Active | Botanical taxonomy only — no care schedules. Not a replacement. |
+| **Wikipedia API** | Active | Returns name, description, thumbnail. No structured care data. |
+| **Google Knowledge Panel** | N/A | Has structured care data but scraping violates ToS and is technically brittle. |
+
+### Future opportunity
+
+Google's plant Knowledge Panels aggregate care data (watering frequency, sunlight, pruning) from sources like The Sill, Bloomscape, Gardenia.net, and others. A curated, structured plant care dataset — particularly one covering common garden plants in NW Europe — does not currently exist as a clean, accessible API. This could be a commercial opportunity: either licensing a dataset or building a plant care API as a product.