e774097fd8
Adds the client-facing endpoint that issues a signed stream URL for
the current track. Authenticated via the standard session cookie.
Returns {token, exp, url} where url is a fully-formed stream URL
the client passes verbatim to a UPnP / Sonos device's
AVTransport.SetAVTransportURI call.
expSeconds clamped to [60, 86400]; default 21600 (6h) - long enough
to play through any typical track without re-minting mid-playback.
MINSTREL_STREAM_SECRET is loaded from env var with a per-machine
fallback persisted at <Storage.DataDir>/stream_secret (auto-generated
on first boot via 64 random bytes, base64-url-encoded, 0600). The
file-based fallback is operator-machine-scoped runtime state, not a
user-facing setting - chosen over a DB column to avoid a migration
and keep the secret out of cross-instance restores. Operator can
override at any time via the env var; default path requires zero
config.
Tests cover happy-path token issuance + URL formatting, bad-UUID
rejection, unauthenticated rejection, the expSeconds clamp at all
boundaries, secret env override, auto-gen + file persistence at 0600,
second-boot reuse of the persisted file, and rejection of a malformed
env value.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>