**feat(compose):** add separate deploy and dev Docker Compose files

- Introduced `compose.yml` for deployment, pulling the image from the registry
- Added `compose.dev.yml` for local development, building the image from source
- Updated `README.md` and `.claude/CLAUDE.md` with instructions for both configurations
- Introduced `DB_PATH` environment variable to customize SQLite database file location
- Updated `main.go` to use `DB_PATH` with a default fallback (`./diun.db`)

.claude/CLAUDE.md

@@ -17,9 +17,12 @@ go run ./cmd/diunwebhook/
 # Build Docker image
 docker build -t diun-webhook-dashboard .
 
-# Run with Docker Compose
+# Run with Docker Compose (deploy — pulls from registry)
 docker compose up -d
 
+# Run with Docker Compose (dev — builds locally)
+docker compose -f compose.dev.yml up -d
+
 # Frontend (from frontend/ directory)
 bun install          # install deps
 bun run dev          # dev server on :5173 (proxies /api and /webhook to :8080)
@@ -56,6 +59,7 @@ The app is a Go HTTP server that receives [DIUN](https://crazymax.dev/diun/) web
 
 **Environment variables:**
 - `PORT` — listen port (default `8080`)
+- `DB_PATH` — path to SQLite database file (default `./diun.db`); set to e.g. `/data/diun.db` in Docker to use a separate mountable directory
 - `WEBHOOK_SECRET` — when set, every `POST /webhook` must include a matching `Authorization` header; when unset, the webhook is open (a warning is logged at startup)
 
 **Key data flow:**