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 because the auth redirect code that drops the query string is unchanged in this PR.

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 sign-in redirect still hardcodes callbackPath=/usage, so a shared /usage?groupBy=model link falls back to the default day view after authentication.
src/lib/user.server.ts	759	appendCallbackPath() only preserves x-pathname, so organization usage links with ?groupBy=model also lose the new URL-backed state during auth redirects.

Files Reviewed (2 files)

• src/app/(app)/usage/page.tsx
• src/components/organizations/usage-details/OrganizationUsageDetails.tsx

---

_{Reviewed by gpt-5.4-20260305 · 403,046 tokens}