feat(web): double-click the right panel divider to split the space evenly - #29206

Eligibility
Double-clicking the right-panel divider now centers the split within existing width limits. The adjustment is user-triggered, locally persisted, and leaves default sizing unchanged.

Additional Thinking

Your Custom Policy

The additional human-review requirements do not apply: the change adds an explicit user gesture rather than changing product defaults, and the assessed diff adds or broadens no static-analysis suppression. Existing suppression directives are unchanged.

Code

Adds a divider double-click handler that sets the preview/right panel width to half its containing row. It uses the existing width setter, preserving minimum/maximum bounds and browser-local width persistence. Existing drag behavior and default width remain unchanged. The ignored file was not reconstructed.

Review Context

Author identity was supplied; ownership information and check results were not. There are no supplied unresolved review comments or correctness findings. Investigation confirmed the handler reaches the inline, non-maximized panel divider and changes only a locally persisted layout preference.

Verdict

The change is a bounded, user-triggered layout adjustment using existing resizing and persistence mechanisms. Users can resize again normally; no external systems or customer content are affected, and no obvious material risk requires human judgment.

Notes:
No code owners found in target merge base 305a90d

Agent Credits: 30 credits
Approvability runs at a flat rate of 30 credits whenever the agent is asked for a verdict.