fix: resolve uv binary path after fresh install in Makefile

The uv installer adds ~/.local/bin/uv but does not update the current
shell PATH. Use the discovered path or fall back to ~/.local/bin/uv
so the subsequent uv tool install succeeds on first run.

Makefile

@@ -103,7 +103,8 @@ install: submodules
 		exit 1; \
 	fi
 	@command -v uv >/dev/null 2>&1 || { echo "uv not found. Installing uv..."; curl -LsSf https://astral.sh/uv/install.sh | sh; }
-	@uv tool install -e .
+	@UV_BIN=$$(command -v uv 2>/dev/null || echo "$$HOME/.local/bin/uv"); \
+		"$$UV_BIN" tool install -e .
 
 update: submodules
 	@uv tool install -e . --force --reinstall