Add Makefile with start target for HTTP serve mode

Provides `make start` to run the llm-connect server via uv, with optional
LLM_CONNECT_* overrides and standard dev targets for install, test, lint,
and typecheck.

Makefile

@@ -0,0 +1,37 @@
+-include .env
+export
+
+.PHONY: install test lint typecheck start help
+
+UV ?= $(shell command -v uv 2>/dev/null || if [ -x "$$HOME/.local/bin/uv" ]; then printf "%s" "$$HOME/.local/bin/uv"; else printf "%s" "uv"; fi)
+
+LLM_CONNECT_HOST ?= 127.0.0.1
+LLM_CONNECT_PORT ?= 8080
+LLM_CONNECT_PROVIDER ?= mock
+LLM_CONNECT_MODEL ?=
+SERVER_ARGS ?=
+
+install:  ## Install dependencies (dev group)
+	$(UV) sync --group dev
+
+test:  ## Run test suite
+	$(UV) run pytest
+
+lint:  ## Run ruff linter
+	$(UV) run ruff check .
+
+typecheck:  ## Run mypy type checker
+	$(UV) run mypy llm_connect
+
+start:  ## Start llm-connect HTTP server (reads .env and LLM_CONNECT_* overrides)
+	$(UV) run python -m llm_connect.server \
+		--host $(LLM_CONNECT_HOST) \
+		--port $(LLM_CONNECT_PORT) \
+		--provider $(LLM_CONNECT_PROVIDER) \
+		$(if $(LLM_CONNECT_MODEL),--model $(LLM_CONNECT_MODEL),) \
+		$(SERVER_ARGS)
+
+help:  ## Show this help message
+	@grep -Eh '^[a-zA-Z_-]+:.*?##' $(MAKEFILE_LIST) | \
+		awk 'BEGIN {FS = ":.*?## "}; {printf "  \033[36m%-16s\033[0m %s\n", $$1, $$2}' | \
+		sort