---
id: T02
parent: S01
milestone: M002
provides: []
requires: []
affects: []
key_files: ["app/src/App.tsx", "app/src/App.css", "app/src/views/ImportConvert.tsx", "app/src/views/ImportConvert.module.css", "app/src/components/FileUpload.tsx", "app/src/components/PresetSelector.tsx"]
key_decisions: ["Use CSS modules for view-specific layout, global App.css for shared component styles", "Underscore-prefix unused state variables to keep them wired for T03 without lint warnings"]
patterns_established: []
drill_down_paths: []
observability_surfaces: []
duration: ""
verification_result: "Ran `cd app && npx tsc --noEmit` — zero TypeScript errors. Ran `cd app && npx vitest run --reporter=verbose` — all 9 existing tests pass."
completed_at: 2026-03-26T05:07:29.816Z
blocker_discovered: false
---

# T02: Built app shell with ViewState routing, drag-and-drop FileUpload with thumbnail preview, PresetSelector fetching from engine API, and two-column ImportConvert layout

> Built app shell with ViewState routing, drag-and-drop FileUpload with thumbnail preview, PresetSelector fetching from engine API, and two-column ImportConvert layout

## What Happened
---
id: T02
parent: S01
milestone: M002
key_files:
  - app/src/App.tsx
  - app/src/App.css
  - app/src/views/ImportConvert.tsx
  - app/src/views/ImportConvert.module.css
  - app/src/components/FileUpload.tsx
  - app/src/components/PresetSelector.tsx
key_decisions:
  - Use CSS modules for view-specific layout, global App.css for shared component styles
  - Underscore-prefix unused state variables to keep them wired for T03 without lint warnings
duration: ""
verification_result: passed
completed_at: 2026-03-26T05:07:29.827Z
blocker_discovered: false
---

# T02: Built app shell with ViewState routing, drag-and-drop FileUpload with thumbnail preview, PresetSelector fetching from engine API, and two-column ImportConvert layout

**Built app shell with ViewState routing, drag-and-drop FileUpload with thumbnail preview, PresetSelector fetching from engine API, and two-column ImportConvert layout**

## What Happened

Created the ImportConvert view (View 1) with a two-column flexbox layout: left panel for controls, right panel for the SVG preview placeholder. Built FileUpload component with drag-and-drop zone using onDragOver/onDrop handlers plus a hidden file input fallback, thumbnail rendering via URL.createObjectURL, file size display, and SVG file detection for mode switching. Built PresetSelector that fetches presets from the engine API on mount with AbortController cleanup, renders preset cards in a 2-column grid with selected state highlighting, and auto-selects 'sign' as the default. Updated App.tsx with a ViewState type union ('import' | 'canvas' | 'export') and conditional rendering. Created App.css with global styles for the upload zone, preset cards, and placeholder views. Wired state in ImportConvert for T03 consumption.

## Verification

Ran `cd app && npx tsc --noEmit` — zero TypeScript errors. Ran `cd app && npx vitest run --reporter=verbose` — all 9 existing tests pass.

## Verification Evidence

| # | Command | Exit Code | Verdict | Duration |
|---|---------|-----------|---------|----------|
| 1 | `cd app && npx vitest run --reporter=verbose` | 0 | ✅ pass | 832ms |
| 2 | `cd app && npx tsc --noEmit` | 0 | ✅ pass | 2000ms |


## Deviations

None. All 6 expected output files created as planned.

## Known Issues

None.

## Files Created/Modified

- `app/src/App.tsx`
- `app/src/App.css`
- `app/src/views/ImportConvert.tsx`
- `app/src/views/ImportConvert.module.css`
- `app/src/components/FileUpload.tsx`
- `app/src/components/PresetSelector.tsx`


## Deviations
None. All 6 expected output files created as planned.

## Known Issues
None.
