feat(command-center): add Brainrot mode for empty cells

[richardsolomou]

Problem

When you have fewer tasks than the grid holds (e.g. three tasks in a 2×2), you're left with an empty cell you can't do anything useful with.

Changes

Add a "Brainrot" option to the empty-cell add-task popover. Instead of an agent task, it fills the slot with a looping background video — a deliberately silly way to occupy the leftover cell.

• New reserved cell sentinel (BRAINROT_CELL) so a slot can hold a video instead of a task id; buildCommandCenterCells surfaces it as isBrainrot and the panel renders a BrainrotCell.
• setBrainrotCell store action — no dedupe, so multiple cells can run it.
• Two clips bundled locally (landscape + portrait, 720p, muted, ~7 MB each). A ResizeObserver hook picks the one matching the cell's orientation, so it fills the space with minimal letterboxing and no zoom. Local hosting means it plays instantly and works offline (no YouTube embed / quality ramp).
• Fires a "Brainrot activated" analytics event with the grid layout and how many cells already held a task, to see whether it's used to fill the leftover slot or on purpose.

How did you test this?

• Unit tests for the pure logic and store action: isBrainrotCell, buildCommandCenterCells (parameterised), and setBrainrotCell. All passing.
• Biome lint + full pnpm typecheck via the pre-commit hook, both clean.
• Have not yet driven it in the running app.

Automatic notifications

• Publish to changelog?
• Alert Sales and Marketing teams?

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Created with PostHog Code

[github-actions]

React Doctor found no issues in the changed files. 🎉

_{Reviewed by React Doctor for commit b609108.}

[greptile-apps]

_{Reviews (1): Last reviewed commit: "feat(command-center): add Brainrot mode ..." | Re-trigger Greptile}