chore: remove hub.rivet.gg references

[NicholasKissel]

• Remove the "Looking for Rivet Enterprise Cloud? Visit hub.rivet.gg" banner from the login and join pages
• Update the SQLite blog post to reference the Rivet dashboard instead of the Rivet Hub

[railway-app]

🚅 Deployed to the rivet-pr-5550 environment in rivet-frontend

Service	Status	Web	Updated (UTC)
kitchen-sink	😴 Sleeping (View Logs)	Web	Aug 6, 2026 at 6:24 am
website	😴 Sleeping (View Logs)	Web	Aug 6, 2026 at 6:23 am
frontend-cloud	😴 Sleeping (View Logs)	Web	Aug 6, 2026 at 6:23 am
frontend-inspector	✅ Success (View Logs)	Web	Aug 6, 2026 at 6:16 am
ladle	✅ Success (View Logs)	Web	Aug 6, 2026 at 6:15 am
mcp-hub	✅ Success (View Logs)	Web	Aug 6, 2026 at 6:15 am

[claude]

Review

Small, well-scoped cleanup PR. Verified against the current CLAUDE.md rivet.dev naming convention.

Changes:

• Removes the "Looking for Rivet Enterprise Cloud? Visit hub.rivet.gg" banner from join.tsx and login.tsx
• Updates the SQLite blog post to say "Rivet dashboard" instead of "Rivet Hub"

Findings:

• No issues. The removed JSX blocks were self-contained (no leftover unused imports/variables in either join.tsx or login.tsx).
• Confirmed no other hub.rivet.gg / "Rivet Hub" references remain in frontend/ or website/ after this change.
• The blog post edit reads correctly in surrounding context (still references the actor database explorer feature accurately).
• Other unrelated rivet.gg references remain (e.g. assets2.rivet.gg, ph.rivet.gg for PostHog, rivet.gg/discord in frontend/src/components/onboarding/footer.tsx, a stories fixture email) — out of scope for this PR since it's specifically targeting the "hub.rivet.gg" / "Rivet Hub" branding, not all rivet.gg usages.

Test coverage: No tests needed for this copy/link removal — appropriate for the scope of the change.

LGTM.