[UX]: make onboarding and dashboard errors more actionable

[MatrixAdventurer]

Summary

Many onboarding and dashboard errors are technically accurate but not actionable enough for end users.

Problem

Messages like these often leave users unsure what to do next:

• invalid API key
• email not received
• no memories found
• auth failed
• connection failed

Suggested improvement

For user-facing onboarding/dashboard errors, include the next recommended action directly in the message.

Examples:

• Invalid API key -> tell the user where to create/regenerate one
• Email not received -> suggest Spam/Junk/Promotions + resend
• No memories found -> suggest checking filters or usage page
• Connection failed -> suggest verifying API URL / key

Why this matters

• Reduces support burden
• Lowers onboarding drop-off
• Makes the product feel more reliable and self-explanatory

Expected behavior

Important user-facing errors should explain both:

1. what went wrong
2. what the user should do next

[MatrixAdventurer]

Linked to umbrella onboarding issue #123. Keeping this open as a concrete actionable-errors task.

[MatrixAdventurer]

Opened PR #128 to improve actionable onboarding/health guidance in the OpenClaw integration path. This does not cover dashboard UI errors, but it does cover repo-local CLI/setup/health messaging.

[MatrixAdventurer]

Status update: PR #128 has been closed as superseded by current main.

That PR covered some repo-local OpenClaw CLI/setup/health messaging improvements, but this issue is still valid because the broader onboarding/dashboard error-message problem remains unresolved.

[MatrixAdventurer]

Additional context: current Memoria Cloud health appears degraded (see #129). Some user-visible connection / health errors during onboarding may currently be amplified by a Cloud-side outage/degraded state.

[MatrixAdventurer]

Relationship note: treating this as a concrete child slice under #123 rather than a duplicate. #123 covers the broader onboarding / activation path; this issue is specifically about making onboarding/dashboard errors actionable enough that users know the next step immediately.