Add disclaimer that we are not affiliated with UP, gwa calculation is not official, etc

[smmariquit]

Status: proposed

Problem

The extension reads grades from AMIS and produces a GWA and Latin-honor projections. Nothing on screen tells the user that this is an unofficial estimate from a tool with no UP affiliation, and nothing warns about the cases where our math and the registrar's will legitimately disagree.

That matters most for non-numeric marks. popup.js treats S, U, INC, DRP, W, P, DFG as non-numeric and excludes them from the computation (see the nonNumericGrades lists around popup.js:256, :440, :874). That is a reasonable default, but an INC that later completes, or a DRP recorded differently on the official record, changes the real GWA and ours will not match. A student deciding whether they are on track for honors should not be reading a number that carries no caveat.

Copy to ship

Not affiliated with UP. Unofficial estimate. INC/DRP may not reflect correctly. Always verify with the OUR.

Where it goes

• Visible in the popup near the GWA result, not buried behind an About link. It should be readable at the moment the number is read.
• Same line on the planner view, which projects future grades and is therefore even further from official.
• Store listing descriptions (Chrome, Firefox, Opera, Edge), since that is where users decide to install.
• README.

Keep it one line and plain. Do not make it dismissible, and do not shrink it to unreadable fine print; the point is that it is seen.

Acceptance criteria

• The disclaimer is visible on the popup and planner without any interaction
• Wording matches the copy above exactly, in every surface
• Store listings carry the same statement
• Readable contrast, no truncation at the extension popup's width