Replace glyph text input with tile button and picker

[lann]

Changes glyph selection from a text input field to a button tile that opens a picker interface, matching the UI pattern for emoji/glyph selection across settings and app sheets.

Changes

visor/src/ui.rs:

• Rename GlyphInput component to GlyphPicker to better reflect its new purpose
• Replace text input with a button tile (glyph-tile-button) that displays the selected glyph
• Move search functionality into the picker, keeping the search field separate from the draft state
• Search field now retains raw input without normalization; normalization applies only to generate the direct candidate result
• Add direct candidate button (normalized grapheme from current search query) as first result when non-empty
• Add "Clear glyph" button inside picker when a glyph is selected
• Simplify state management: remove raw and input_revision signals; composition events now only control search behavior

visor/src/style.rs:

• Rename #visor-app-glyph to .glyph-tile-face (class-based for reusability)
• Replace .glyph-input with .glyph-control as container
• Add .glyph-tile-button styles (minimal padding, transparent background, 44px minimum touch target)
• Add pointer-events: none to .glyph-tile-face inside button
• Add .glyph-clear button styling inside picker
• Fix #visor-circle with overflow: clip for proper border-radius clipping

e2e/run.ts:

• Update test selectors: replace input field queries with button tile and picker searches
• Change field interaction from fill() to click() + picker navigation
• Update assertions from inputValue() to textContent() for the tile
• Update search placeholder text from "Search emoji" to "Enter glyph or search"
• Add tests for direct candidate selection, compound queries, composition handling, and "Clear glyph" action
• Verify that picker search does not mutate draft state
• Add mobile viewport tests for picker interaction