Constrains the per-client SSE identifier introduced in #86 to
`[A-Za-z0-9_-]{8,64}` at both ingress points (`GET /api/events`
query and `POST /api/events/subscribe` body). Without this, an
authenticated attacker could:
- Send a victim's clientId to silently evict their tab from
sseClients (DoS — socket stays open, broadcasts stop).
- Mutate any clientId's session filter, blackholing that tab's
terminal stream.
- Grow sseClientsById without bound via long IDs.
Also caps the subscribe payload to 64 session entries of ≤128 chars
each, since the previous handler accepted arbitrary-length arrays.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
