Add self-deploying setup scripts for all sub-projects (P1-P8)

- Root setup.sh orchestrator with per-phase dispatch (./setup.sh p1..p8 | all | status)
- Makefile convenience targets (make infra, make llm, make status, etc.)
- scripts/common.sh: shared bash library for OS detection, Docker helpers,
  service management (launchd/systemd), package install, env management
- .env.example + .gitignore: shared config template and secret exclusions

P1 (homeai-infra): full implementation
- docker-compose.yml: Uptime Kuma, code-server, n8n
- Note: Home Assistant, Portainer, Gitea are pre-existing instances
- setup.sh: Docker install, homeai network, container health checks

P2 (homeai-llm): full implementation
- Ollama native install with CUDA/ROCm/Metal auto-detection
- launchd plist (macOS) + systemd service (Linux) for auto-start
- scripts/pull-models.sh: idempotent model puller from manifest
- scripts/benchmark.sh: tokens/sec measurement per model
- Open WebUI on port 3030 (avoids Gitea :3000 conflict)

P3-P8: working stubs with prerequisite checks and TODO sections

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

homeai-llm/docker/docker-compose.yml

@@ -0,0 +1,45 @@
+---
+# homeai-llm/docker/docker-compose.yml
+# P2 — Open WebUI
+#
+# Ollama runs NATIVELY (not in Docker) for GPU acceleration.
+# This compose file only starts the Open WebUI frontend.
+#
+# Prerequisites:
+#   - Ollama installed and running on the host at port 11434
+#   - `homeai` Docker network exists (created by P1 setup)
+#
+# Usage:
+#   docker compose -f docker/docker-compose.yml up -d
+
+name: homeai-llm
+
+services:
+
+  # ─── Open WebUI ──────────────────────────────────────────────────────────────
+  open-webui:
+    container_name: homeai-open-webui
+    image: ghcr.io/open-webui/open-webui:main
+    restart: unless-stopped
+    ports:
+      - "3030:8080"             # Exposed on 3030 to avoid conflict with Gitea (3000)
+    volumes:
+      - ${DATA_DIR:-~/homeai-data}/open-webui:/app/backend/data
+    environment:
+      # Connect to Ollama on the host
+      - OLLAMA_BASE_URL=http://host.docker.internal:11434
+      - WEBUI_SECRET_KEY=${WEBUI_SECRET_KEY:-changeme_random_32_char}
+      - ENABLE_SIGNUP=true
+      - DEFAULT_MODELS=llama3.3:70b
+    extra_hosts:
+      - "host.docker.internal:host-gateway"  # Linux compat
+    networks:
+      - homeai
+    labels:
+      - homeai.service=open-webui
+      - homeai.url=http://localhost:3030
+
+networks:
+  homeai:
+    external: true
+    name: homeai