Build on Go 1.27

Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.26 AS build
+FROM golang:1.27 AS build
 WORKDIR /src
 COPY go.mod go.sum ./
 RUN go mod download

README.md

@@ -9,7 +9,7 @@ Web apps for the Helios school community (K-8), served as one static Go binary o
 
 Open http://localhost:8080. That's the whole setup: with no configuration the server loads the fictional community in `sampledata/`, signs every request in as a sample parent, and fakes geocoding — no credentials, no cloud project. Templates, static assets, and sample data are read from disk on every request, so edit a file and refresh; nothing needs restarting.
 
-`brew install --cask google-chrome` additionally enables the screenshot tooling used to verify visual changes ([docs/screenshots.md](docs/screenshots.md)). No Node, no Docker. Go 1.26 or later.
+`brew install --cask google-chrome` additionally enables the screenshot tooling used to verify visual changes ([docs/screenshots.md](docs/screenshots.md)). No Node, no Docker. Go 1.27 or later.
 
 To run against real community data instead, see [docs/dev.md](docs/dev.md).
 

docs/dev.md

@@ -35,7 +35,7 @@ Development happens on macOS. Two Homebrew installs cover everything here and in
     brew install go
     brew install --cask google-chrome
 
-- **Go** 1.26 or later — builds and runs the server and all tooling (`go run`, `go vet`).
+- **Go** 1.27 or later — builds and runs the server and all tooling (`go run`, `go vet`).
 - **Google Chrome** — launched headless by the screenshot tool from its standard install location; never opened by hand.
 
 No Node, no Docker, and no cloud credentials are needed for local development. Repository layout is in the README.

go.mod

@@ -1,6 +1,6 @@
 module heliosian
 
-go 1.26
+go 1.27
 
 require (
 	github.com/chromedp/cdproto v0.0.0-20260714215040-dc233986426f