fix(ui): persist selected usage view across refreshes

[shssoichiro]

Summary

Currently the Usage page will always reset to the "By Day" view when a user refreshes the page. This change persists the user's selected view by using a query parameter, so that "By Model & Day" can have a permanent URL.

Verification

• Login and go to the Usage page
• Select "By Day & Model"
• Refresh the page
• Ensure that "By Day & Model" is still the active view after refresh

Note that I was not able to manually e2e verify the changes myself, even following the instructions in DEVELOPMENT.md. I suspect it is because I don't have vercel access.

Visual Changes

N/A

[kilo-code-bot]

Code Review Summary

Status: 2 Issues Found | Recommendation: Address before merge

Overview

Severity	Count
CRITICAL	0
WARNING	2
SUGGESTION	0

Fix these issues in Kilo Cloud

Issue Details (click to expand)

No new issues are inline-commentable; the remaining regressions are in unchanged auth redirect code that this PR now depends on.

Other Observations (not in diff)

Issues found in unchanged code that cannot receive inline comments:

File	Line	Issue
src/app/(app)/usage/page.tsx	178	The new URL-backed groupBy state is still dropped on auth failures because the redirect hardcodes callbackPath=/usage, so a shared /usage?groupBy=model link returns on the default day view after sign-in.
src/lib/user.server.ts	759	appendCallbackPath() still serializes only x-pathname, so organization usage links like /organizations/:id/usage?groupBy=model lose the query string during the server-side auth redirect and return on the default day view.

Files Reviewed (2 files)

• src/app/(app)/usage/page.tsx - 1 issue
• src/components/organizations/usage-details/OrganizationUsageDetails.tsx - 0 issues

---

_{Reviewed by gpt-5.4-20260305 · 424,007 tokens}