feat: add Docker support and inbound webhooks (Tier 2)

- Dockerfile: multi-stage build (node:22-alpine), better-sqlite3 native deps handled
- .dockerignore + docker-compose.yml for deployment
- FLYNN_DATA_DIR env var support in daemon, CLI, and TUI
- WebhookHandler: ChannelAdapter for HTTP POST /webhooks/:name
- Per-webhook HMAC auth, template rendering ({{body}}, {{json.field}})
- Config schema: automation.webhooks array with name/secret/message/output
- Gateway routes webhook requests before static files (bypasses gateway auth)
- 23 new tests for webhook functionality, 874 total tests passing

Dockerfile

@@ -0,0 +1,72 @@
+# ── Builder stage ──────────────────────────────────────────────
+FROM node:22-alpine AS builder
+
+# Enable corepack for pnpm
+RUN corepack enable && corepack prepare pnpm@latest --activate
+
+# Install native build tools (needed for better-sqlite3)
+RUN apk add --no-cache python3 make g++
+
+WORKDIR /app
+
+# Copy dependency manifests first (layer caching)
+COPY package.json pnpm-lock.yaml pnpm-workspace.yaml ./
+
+# Install dependencies (frozen lockfile for reproducibility)
+RUN pnpm install --frozen-lockfile
+
+# Copy source and config
+COPY tsconfig.json ./
+COPY src/ src/
+COPY config/ config/
+
+# Build TypeScript
+RUN pnpm build
+
+
+# ── Runtime stage ─────────────────────────────────────────────
+FROM node:22-alpine
+
+# Label
+LABEL org.opencontainers.image.title="Flynn" \
+      org.opencontainers.image.description="Self-hosted personal AI agent" \
+      org.opencontainers.image.source="https://github.com/will666/flynn"
+
+WORKDIR /app
+
+# Copy node_modules from builder (includes compiled native deps like better-sqlite3)
+COPY --from=builder /app/node_modules/ node_modules/
+
+# Copy compiled output
+COPY --from=builder /app/dist/ dist/
+
+# Copy gateway UI static files into dist/gateway/ui so import.meta.dirname
+# resolution from dist/daemon/index.js (../gateway/ui) resolves correctly
+COPY --from=builder /app/src/gateway/ui/ dist/gateway/ui/
+
+# Copy default config
+COPY --from=builder /app/config/ config/
+
+# Copy package.json (needed for bin resolution / metadata)
+COPY --from=builder /app/package.json ./
+
+# Copy SOUL.md if it exists (prompt template loaded at runtime)
+COPY --from=builder /app/SOUL.md ./
+
+# Create data directories
+RUN mkdir -p /data/memory /data/sessions /config
+
+# Environment
+ENV NODE_ENV=production \
+    FLYNN_CONFIG=/config/config.yaml \
+    FLYNN_DATA_DIR=/data
+
+# Gateway port
+EXPOSE 18800
+
+# Health check — verify the gateway is responding
+HEALTHCHECK --interval=30s --timeout=5s --start-period=15s --retries=3 \
+  CMD wget -qO- http://localhost:18800/ || exit 1
+
+ENTRYPOINT ["node", "dist/cli/index.js"]
+CMD ["start"]