feat: phase 7 automation & realtime — scheduled jobs, domain events, SSE

Scheduled jobs (migration 00009): cron expressions + @every descriptors,
in-process scheduler (15s scan, missed-run collapse), signed HTTP POST
delivery (X-Primora-Signature), AES-256-GCM sealed secrets returned once,
run history with status/duration/http-code, manual execution, retention
pruning. Viewer reads, admin/developer writes.

Domain events: publishEvent fans document/object/issue/deploy/job
mutations to realtime subscribers and matching webhooks through one
path. Webhook event filter extended to job.run, document.*, object.*.

Realtime: GET /projects/:id/realtime/stream SSE with 25s keepalives and
?token=/?api_key= auth for EventSource clients.

Automation dashboard page: Schedules tab (CRUD, run history, manual run,
secret-once banner) + Live events tab (live badge, pause/clear). Demo
mode parity. primora jobs:* CLI group, six primora_*_job* MCP tools,
AutomationService in the generated client.

Fixes folded in: gzip middleware buffered SSE flushes (broke EventSource
on both streams — */stream now bypasses compression); event payloads
double-marshaled json.RawMessage as base64; compose hardcoded localhost
trusted origins so non-default ports broke sign-in; frontend auth base
URL baked an absolute localhost instead of resolving /auth on origin.

Verified live: stack up on :8085, signed delivery HMAC-checked at sink,
@every 30s schedule firing, run history rendering, document.created
landing in the live events feed.

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

apps/backend/go.sum

@@ -104,6 +104,8 @@ github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec h1:W09IVJc94
 github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec/go.mod h1:qqbHyh8v60DhA7CoWK5oRCqLrMHRGoxYCSS9EjAz6Eo=
 github.com/resend/resend-go/v2 v2.15.0 h1:B6oMEPf8IEQwn2Ovx/9yymkESLDSeNfLFaNMw+mzHhE=
 github.com/resend/resend-go/v2 v2.15.0/go.mod h1:3YCb8c8+pLiqhtRFXTyFwlLvfjQtluxOr9HEh2BwCkQ=
+github.com/robfig/cron/v3 v3.0.1 h1:WdRxkvbJztn8LMz/QEvLN5sBU+xKpSqwwUO1Pjr4qDs=
+github.com/robfig/cron/v3 v3.0.1/go.mod h1:eQICP3HwyT7UooqI/z+Ov+PtYAWygg1TEWWzGIFLtro=
 github.com/rogpeppe/go-internal v1.14.1 h1:UQB4HGPB6osV0SQTLymcB4TgvyWu6ZyliaW0tI/otEQ=
 github.com/rogpeppe/go-internal v1.14.1/go.mod h1:MaRKkUm5W0goXpeCfT7UZI6fk/L7L7so1lCWt35ZSgc=
 github.com/rs/xid v1.6.0/go.mod h1:7XoLgs4eV+QndskICGsho+ADou8ySMSjJKDIan90Nz0=