Closes the three "platform-impossible" gaps from the design audit
without resorting to hacks or shaders.
* chrome::glass — `render_inner_highlight(radius)` paints the design's
`box-shadow: inset 0 0 0 1px` ring as an absolute overlay div with a
1 px top-edge highlight sliver. GPUI 0.2.2's BoxShadow has no inset
flag, so the composite is the only way to keep the panel content
unclipped while the ring rides on top.
* chrome::animations — `blink` and `fade_in` wrap GPUI's first-class
`with_animation` driver. Square-wave caret in the command header,
180 ms opacity ramp on the command backdrop and workspace
disclosure list.
* chrome::sidebar — panel_bg now tints toward the active wallpaper
theme so the wallpaper bleeds through every glass surface, the
closest honest substitute for backdrop-filter without a shader pass.
* command_overlay split: row helpers move to chrome::command_rows so
command_overlay drops from 504 → 232 lines, well under the 500-line
ceiling. No behavior change.
cargo test --workspace: 440 passed, 0 failed.
ZacharyZhang-NY