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-infra/docker/.env.example

@@ -0,0 +1,12 @@
+# homeai-infra Docker secrets
+# Copy to .env — never commit .env
+
+DATA_DIR=${HOME}/homeai-data
+
+# ─── code-server ───────────────────────────────────────────────────────────────
+CODE_SERVER_PASSWORD=changeme123
+
+# ─── n8n ───────────────────────────────────────────────────────────────────────
+N8N_BASIC_AUTH_USER=admin
+N8N_BASIC_AUTH_PASSWORD=changeme123
+N8N_ENCRYPTION_KEY=changeme_random_32_char_string