Web: Streamlit Planner — seq length sweep

The Streamlit planner is the browser-native cousin of hwledger plan: a golden model fixture on one side, a stacked VRAM chart on the other, and live sliders for sequence length, concurrent users, and quantisation wired into the same FFI the CLI uses.

What you'll see

This journey opens the DeepSeek-V3 fixture, sweeps the sequence-length slider upward from 4K tokens, and watches the stacked VRAM bar chart re-render. The KV cache band grows roughly quadratically with context — the whole point of the planner is that the operator sees that growth before deploying.

Narrative beats:

1. Planner lands with the default fixture; the sidebar exposes seq length, concurrent users, and KV + weight quantisation.
2. Sidebar expanded, slider focused at the default 4096 tokens.
3. Slider bumped; the stacked VRAM chart re-renders with a visibly taller KV band.
4. Scrolling down reveals the per-layer KV contribution heatmap.
5. Further scroll reveals the export row — vLLM / llama.cpp / MLX buttons.

Journey not yet recorded.

Run the journey recorder to capture interactions:

./apps/macos/HwLedgerUITests/scripts/run-journeys.sh

Reproduce

# One-shot: boot Streamlit, run Playwright, transcode video, write manifests.
cd apps/streamlit/journeys
bun install
bash scripts/record-all.sh
bash scripts/verify-manifests.sh

# Just Playwright (Streamlit already running on 8599):
STREAMLIT_URL=http://127.0.0.1:8599 bunx playwright test specs/planner.spec.ts

See apps/streamlit/journeys/README.md for the full harness.