Why: The embedded tier starts without auth, and nothing checked Origin or Host, so a public bind or a foreign page could call write APIs.
Evidence: go test ./internal/config ./internal/server covering listen policy, origin rejection, and response headers.
Impact: Non-loopback without auth exits before opening the database. HTML artifacts get a sandbox CSP. Reverse proxies must list their public host in allowedHosts.
Refs: feature/sillytavern-review
Co-authored-by: Cursor <cursoragent@cursor.com>
Why: startup had only defaults and CLI flags; dev/test/prod operation needs
the standard baseline (explicit file, environment, explicit-only CLI) and a
read-only diagnostic.
Evidence: internal/config unit tests cover precedence, unset-CLI no-override,
presence-based file semantics, unknown-key/missing-file errors, env bool
parsing, explain source labelling and DSN redaction; full suite 12 packages
pass; live run of config explain with envs/prod.json shows correct layer
attribution and redaction.
Impact: serve gains --config and AGENT_SYSTEM_* env overrides (behavior
unchanged when neither is used); new config explain subcommand; envs/
examples and PROJECT.md configuration section.
Refs: documents docs/proposals/2026-09-30-configuration-surface.md; standards/configuration.md
weichenandCursor