[joshpitzalis]

Summary

Add a local Hindi tracing preview to the Void/React scaffold. A learner can draw separate gestures, reveal ordered reference strokes, clear, and retry. The original development letter is visibly marked review pending.

checked-in lesson → Effect content boundary → React/SVG practice
                                             ├─ local pointer ink
                                             ├─ reveal / clear / retry
                                             └─ interruption recovery
commit + CI → strict types / Effect diagnostics / boundaries / tests / build

Closes #2. Tracks #1 and #3; #3 remains open for human lesson review and device evidence. #4 and #5 remain blocked. Specification: SPEC.md.

Evidence

• Before: the generated welcome page had no Strokes practice surface; drawing checks failed without live ink.
  After: browser checks exercise visible live ink, separate gestures, Clear/Retry, Reveal, secondary pointers, cancellation, capture loss, blur, release outside, and resize recovery/alignment.
• Invalid lesson content is rejected before practice; a rendering check verifies the separate lesson-unavailable message without handwriting feedback or drawing controls.
• Phone and desktop layout checks include a square pad; phone-size drawing and keyboard reset/focus are covered in Chromium.
• pnpm check, pnpm test, and pnpm build pass locally with real pre-commit hooks. The fence probes intentionally invalid types, floating Effects, forbidden imports, and browser globals in domain code. CI repeats frozen installation and check/test/build.
• The delegated visual direction is recorded in PRODUCT.md, DESIGN.md, its sidecar, and the surface contract. Phone and desktop screenshots received a separate Impeccable review. The one detector pass reported only provisional-token documentation advisories; the design documentation now records the actual values.

Remaining gates

• The original ल development template still needs a competent Hindi writer or teacher to review its shape, pen lifts, directions, headline, and teaching order. No pedagogical validity is claimed.
• This preview does not check strokes or complete a checked exercise. The specification requires Trace, reveal, and retry one reviewed Hindi letter #3's review gate before Check each stroke and complete the letter #4 starts.
• Finger/stylus calibration, actual iPhone Safari and Android Chrome checks, and deployment remain unverified. Browser emulation does not establish real-device success.
• The separate lesson-catalog/progress specification is outside this PR. Attempts stay in memory; there are no uploads, accounts, stored progress, or cloud data resources.

Merge Danger

Door: two-way

No stored learner data or migrations. Reverting removes the local preview and scaffold.

Blast Radius: practice

Introduces the toolchain, local drawing page, hooks, and CI. This draft remains an incomplete implementation of the full checked-exercise specification.