Implement the following plan:

# Writing-First Home Page

## Context

The home page currently shows the meditation timer as the default view, with writing hidden behind a FAB. The user wants the opposite: writing is the core of anky — a journal — so the writing textarea should be front and center when you land. Meditation becomes a secondary action via a FAB. The time picker's arrow buttons are also tedious — replace with native scrollable number inputs.

## Changes

### 1. `templates/home.html` — Flip default visibility

- **Writing container**: Remove `style="display:none"` — visible by default, textarea auto-focused
- **Meditation scene**: Add `style="display:none"` — hidden by default
- **FAB**: Change from pen/write icon to a meditation icon (simple circle/lotus). Click opens the meditation overlay instead of write mode.

### 2. `templates/home.html` — Replace time picker with native inputs

Replace the arrow-button picker with two `<input type="number">` fields (minutes 0-99, seconds 0-59). On mobile these give native scroll/stepper UX. Remove the arrow button markup and JS.

### 3. `templates/home.html` — Update JavaScript

- FAB click → show meditation scene overlay (instead of `enterWriteMode()`)
- Writing textarea auto-focuses on page load
- Add close/back button on meditation overlay to return to writing
- Post-meditation "write" option hides meditation and returns to writing view
- `resetToMed` renamed/adjusted → returns to writing view (hides meditation scene)
- `enterWriteMode` still exists but is simplified (just hides meditation if visible)

### 4. `static/style.css` — Adjust styles

- FAB: hide during meditation (not during writing)
- Writing container visible by default
- Style the native number inputs to match the dark theme
- Med-scene keeps fullscreen overlay styling (z-index 50), just starts hidden

## Files to modify

1. `templates/home.html` — template structure + JS logic
2. `static/style.css` — FAB visibility, picker input styling

## Verification

1. `cargo build --release && systemctl --user restart anky.service`
2. Open anky.app → writing textarea visible immediately
3. FAB in bottom-right → click → meditation overlay appears
4. Tap timer → number inputs for min:sec (scrollable on mobile)
5. Complete meditation → "write" returns to writing view
6. Writing session works as before (8s idle, checkpoints, chat)