Handle empty and single-data-point states across the dashboard

[dubemoyibe-star]

Context

The UI is built against the current happy path: two protocols, each with accumulated history. Several states aren't handled — a freshly deployed environment with no runs recorded, a newly added protocol with a single score, a protocol whose only runs have failed. A history chart with one data point, or a registry with zero rows, shouldn't render as a broken layout or an empty box with no explanation.

Scope

In scope: audit every data-driven view for empty, single-point, and all-failed states, and give each a deliberate rendering with an explanation of what's happening.
Out of scope: changing the API contract or what data gets returned.

Acceptance criteria

• Registry with zero protocols renders a clear explanatory state, not an empty table
• Protocol detail with no successful runs explains that scoring hasn't succeeded yet rather than showing null or zero as if it were a score
• History chart handles zero and one data point without breaking layout
• A never-scored protocol is visually distinct from one scoring badly — a missing score and a low score must not look the same
• States verified by actually forcing them locally, not just reasoned about

Difficulty

Intermediate — needs familiarity with the codebase or methodology

Notes / open questions

The fourth criterion is the important one. A user misreading "no data yet" as "this protocol scored zero" would be actively misleading, which matters more here than in most products.

[waterWang]

I'd like to work on this. My plan:

1. Audit every data-driven view for empty/single-point/all-failed states
2. Registry zero-protocol state: render a clear explanatory message instead of an empty table
3. Protocol detail with no successful runs: show "scoring hasn't succeeded yet" instead of null/zero
4. History chart: handle 0 and 1 data point without breaking layout
5. Never-scored vs scored-badly distinction: ensure missing score ≠ low score visually

I'll start by forcing each state locally to verify the fixes.