Replace the legacy AngularJS <log-viewer> on the container logs page with a
modern React log viewer, reusing the existing streaming (#6) and formatting/
coloring pipeline. Features: line-number gutter, zerolog level + key=value
coloring (from the existing formatter spans), from/to datetime range, Lines
limit, Line numbers / Timestamp / Wrap lines toggles, Auto refresh (live tail
on/off), Search + 'Filter search results', Copy, Download logs, and fullscreen.
The viewer is source-agnostic (StreamLogsFn), so service/task logs can adopt it
later; this PR wires container logs only. containerLogsController.js no longer
opens its own live stream (React owns fetching now), preventing a double stream.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
