## Problem
The API Gateway report initializes its request range with the Logs
Explorer helper, which leaves `iso_timestamp_end` empty. When an OTEL
chart returns sparse microsecond timestamps, the time series filler can
interpret them as milliseconds while deriving the end of the range and
attempt an unbounded fill, freezing or crashing the browser tab.
## Fix
Initialize the report with its date range helper so both request bounds
are present. Normalize microsecond timestamps before deriving fill
bounds, including the single point case. Add regression tests for sparse
OTEL data with both empty and explicit end dates.
## How to test
- Open Observability → API Gateway on a project with requests spanning
two hourly buckets. The page should render without a tab crash, and the
analytics requests should include a nonempty `iso_timestamp_end`.
- Run `pnpm --filter studio exec vitest run
tests/features/logs/Logs.utils.test.ts` and confirm the microsecond
timestamp cases pass.
- Run the Studio typecheck and lint checks.
The Vitest, typecheck, and lint commands could not run in this worktree
because Studio dependencies are not installed. The source diff passed
`git diff --check` and received a focused code review.
Jordi Enric
881c124301