T20: Debug

- DebugToolbar, BreakpointList, CallStack with folded library frames, ThreadList
- VariablesPanel and WatchPanel, colored by kind, changes washed
- HexViewer at a base address with the byte under the pointer lit on both sides
- Disassembly with source lines, registers and numbers colored, gutter breakpoints
- Flamegraph that zooms by frame, TimelineProfiler that zooms and pans by wheel
- NetworkInspector with a waterfall, a filter and a request's headers and body
- icons: redo-dot, arrow-down-to-dot, arrow-up-from-dot
- gallery: the Debug page

AGENTS.md

@@ -109,6 +109,7 @@ Ely GPUI Component. A component library for GPUI, in light and dark.
 - Charts lay out in `f32` pixels of their own box, tested without gpui, and paint through `charts::paint::at`: a canvas's paint gets window coordinates, and `with_element_offset` works only in prepaint. Their sizes come from `theme.chart()`.
 - A label pinned to a point sits in a zero-size absolute box that centers it with flex (`charts::axes`), so no offset guesses at text size.
 - Tokens live in `src/theme`; the raw `px()` scan skips that folder only.
+- A callback field holds a named `type` alias; clippy's type_complexity rejects `Option<Rc<dyn Fn(..)>>`. A chapter shares one alias per shape.
 - A terminal takes Tab and Shift-Tab through bindings under `ElyTerminal`, ahead of focus moves; other keys go through `terminal::keys` in a key listener, and typed text through its input handler.
 - A shell in the gallery starts without startup files and with a fixed prompt, so captures show no user or host.
 - gpui 0.2.2 has no `(ElementId, usize)` id. A child id names its index: `(self.id.clone(), format!("row-{ix}"))`.