Browsers allow about six HTTP/1.1 connections to a host and an open
EventSource holds one. Sharing a stream per URL was not enough: a
dashboard with six modules still ran out — Safari first — and every later
request (a remounted tile's /state, an avatar) waited in the browser's
queue for ever; a Timers clock tile went blank after any settings change.
The page now holds ONE EventSource, GET /api/stream?s=<keys>, naming the
streams it wants (`slack:/stream`, `shell:` for the shell's own events).
The server relays each module stream into it over loopback — module
routes are untouched and still serve curl — prefixing every event name
with its key, and brackets each stream's life with `<key>|__open` and
`<key>|__down` (re-opened after a pause). sseSubscribe keeps its shape:
subscribers see their events by their own names, a stream joining the
connection is remade with the new list a moment later, and every stream
announces `open` again after it so backfills run as before.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
