Adds a SecurityHeaders middleware and registers it globally, right after the request ID middleware, so every route gets the headers, including static files, /metrics and error responses.
It sets Strict-Transport-Security (one year, includeSubDomains), a Content-Security-Policy with default-src 'self', no scripts and frame-ancestors 'none', X-Frame-Options DENY, X-Content-Type-Options nosniff, Referrer-Policy no-referrer and a Permissions-Policy that turns every listed feature off.
HSTS is sent on every response, not only over TLS: the service runs behind a TLS-terminating proxy and REPO_POLICIES.md requires the application to send it. Referrer-Policy is stricter than the policy baseline because dashboard URLs can name internal hosts.
model: claude-opus-4-8 (implementation); claude-fable-5 (commit message)
Tests for the three packages that had none, written from outside each package, each able to fail on a plausible break:
- globals: values set are read back through New, and New returns an independent copy. One sequential test function with a disclosed paralleltest suppression, because it changes shared package variables.
- healthcheck: Check returns status "ok", the documented JSON fields, an RFC3339Nano timestamp, the maintenance flag from config in both states, and version and appname from globals.
- logger: New gives a usable *slog.Logger, debug output is off by default and EnableDebugLogging turns it on.
No production code changed. The terminal output format is not asserted.
Model: opus-4-8
go.mod listed golang.org/x/sync v0.19.0 twice: once in the direct
require block and once as // indirect. The module is a genuine direct
dependency (internal/portcheck/portcheck.go imports
golang.org/x/sync/errgroup), so the indirect entry was redundant and
stale. script/bootstrap ends with go mod download, which dropped that
line as a side effect and left every fresh checkout with a dirty
go.mod. Running go mod tidy removes the line for good; no dependency
and no version changed, and go.sum is unaffected.
Model: opus-4-8