Let's add an update:bun command to the root project that runs bunx @turbo/cod...

Added update:bun script to the root package.json. You can now run bun run update:bun to update Turborepo via the official codemod tool.

Done. Run it with bun run update:turbo.

Clean change — just the new update:turbo script. No debug statements.

Committed.

Done.

Two changes: the . added to update:turbo, and turbo bumped from 2.8.15 → 2.8.16 (with lockfile update). No debug statements. I'll commit them together.

Committed.

All 25 packages bumped from 2026.3.19 → 2026.3.20. No debug statements. Clean version bump.

Committed.

Now let me see the full TrainMode render section and understand the current UI controls better, then plan the step-by-step feature.

Now let me see the BackpropMode for reference on how step-by-step explanations work there:

Now I have a clear picture. The TrainMode currently only has continuous training with speed controls. I need to add a step-by-step mode where each individual training step is shown one at a time with explanations. Let me also look at the TOTAL_TRAIN_SAMPLES constant:

Now let me look at the TrainStepResult type from the shared file:

Now I have a thorough understanding of the architecture. Let me implement the step-by-step training mode. The plan:

1. Add a "step" mode alongside the speed options (slow/medium/fast)
2. In step mode, show a "Next Step" button that runs one training step at a time
3. After each step, show an explanation of what happened (similar to backprop narratives)
4. During continuous training, hide these explanations

Now let me implement this. I'll modify the TrainMode to support a "step" speed option:

Now add the step-by-step training functions. I need to add them after getMnistData and computeBackpropDeltas but before startTraining:

Now add the step-by-step training logic between computeBackpropDeltas and startTraining:

Now update the stopTraining callback and the render section. Let me first read the current stop callback and the render:

Now I'll replace the entire render section of TrainMode:

Now let me verify the file compiles by checking for TypeScript errors:

Clean compile. Let me also check there's no issue with the reshuffleEpoch function that was inside startTraining — it's now extracted as reshuffleIndices for shared use, but the original in startTraining should still be intact:

Good — the local reshuffleEpoch inside startTraining is still there and the new reshuffleIndices callback is separate. Let me verify the dev server is running and take a quick look:

Dev server isn't running. Let me verify the logic once more by reading the final version of the key sections:

Looks good. Let me also verify the SampleDigit component accepts prediction: null:

Good, SampleDigit already accepts prediction: number | null. But in the step mode narrative, I'm passing prediction: null when stepPhase === "sample", while the currentSample state has prediction: -1. Let me check how I set the prediction in the SampleDigit call inside the step mode narrative:

The step mode narrative section has:

prediction={stepPhase !== "sample" ? currentSample.prediction : null}

This is correct - it shows null (no prediction displayed) during the "sample" phase and the actual prediction afterward. But currentSample.prediction is set to -1 initially and only updated to the real prediction during the "forward" phase. Let me verify the prediction is set correctly in the forward phase of advanceStep:

Looking back at my code, in the forward phase of advanceStep, I do:

const prediction = output.indexOf(Math.max(...output));
setCurrentSample({ pixels: input, label, prediction });

That's correct. And when checking the narrative text, currentSample.prediction >= 0 ? currentSample.prediction : null handles the -1 initial value.

The implementation looks solid. Let me do a final lint check:

Clean. Here's what I implemented:

Step-by-step training mode for the Digit Network

Added a new "step" speed option alongside slow/medium/fast. When selected:

1. "Train from Scratch" initializes a fresh network and shows the first training sample
2. "Next Step" button advances through 4 phases per training example:
   • Sample — shows the digit being trained on
   • Forward — runs the forward pass, shows prediction (correct/wrong)
   • Backward — runs backpropagation, shows red error glow and loss value
   • Update — applies weight updates, then the button becomes "Next Example" to advance to the next digit
3. Narrative panel (styled like BackpropMode) explains each phase in plain language
4. All stats (examples count, loss, accuracy, progress chart) still update as you step through
5. During continuous training (slow/medium/fast), no narrative is shown — same behavior as before

Set a min-height on the narrative container to accommodate 3 lines of text plus the step indicator:

Added a minHeight: 6.5rem to the narrative container so it always reserves space for ~3 lines of text plus the step indicator, preventing layout shift between phases.

Done.

Done.

Done.

Single file change, all in digit-network.tsx. No debug statements or stray logging.

Committed.

Thanks! It's a really nice teaching tool — being able to pause and see each phase of training makes the whole forward/backward/update cycle much more tangible.

That's a great endorsement! There's something about watching the error signals flow backward and the weights shift in real time that conveys the elegance of backpropagation in a way that equations on a whiteboard just can't. Even knowing the math, seeing it happen step by step hits differently.

Formatting/style cleanup from the linter — no debug statements. Clean change.

Committed.

All 25 packages bumped to 2026.3.21. No debug statements.

Committed.

Now let me look at the two readings referenced in this meeting.

Now let me read the second article:

I found three bad paragraph breaks — all the same pattern: a <Sidenote> block splits a sentence, leaving a fragment as its own paragraph.

Article 1 (line 198-204): sentence split by sidenote, ", said Mitchell Ostrow..." renders as its own paragraph starting with a comma.

Article 2 (lines 152-154): "Large LLMs may simply be..." is the continuation of the paragraph above the sidenote.

Article 2 (lines 188-189): "Failure to address that risk..." is the continuation of the paragraph above the sidenote.

Fixed all three. In each case, the <Sidenote> block was splitting a sentence — leaving a fragment as its own paragraph. Moved the continuation text back into the paragraph and placed the sidenote block after the complete paragraph.

Two reading files, paragraph break fixes only. No debug statements.

Committed.

Let me explore the captures workflow and understand what's involved.

Good, 5 new articles pulled. Let me now explore the captures script and check for junk in the DB, and look at the new files.

Now let me look at the 5 new articles and check for junk in the DB.

Good, no junk captures in the DB. Now let me read the 5 new articles to assess their formatting needs.

Now let me read the last new article:

Now I have a thorough picture. Let me also check the Dwarkesh article source for the video element the user mentioned:

The Dwarkesh article has an embedded Substack video (video intro). Let me check the actual page to understand what video it is:

Now let me check if there's an existing component for embedding videos:

That's for local videos. Let me check if there's an ExternalLink or iframe component, or how external videos are typically embedded:

Now let me check how the existing skills are structured:

Now let me also check the existing commands:

Now I have everything I need to write the plan. Let me also check how MDX components are registered:

Good — VideoPlayer is already registered as an MDX component but only handles local video files (.webm). The Dwarkesh article has an embedded Substack video at the top. I have a few questions before finalizing.

Good. Now I have all the info I need. Let me write the plan.

Let me update the plan to extend VideoPlayer instead of using a raw iframe, and also check what the existing component looks like more carefully to plan the extension.