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

tasks/ch11-20.md

@@ -379,16 +379,16 @@
 
 ## T20 Debug — `src/debug`
 
-- [ ] DebugToolbar
-- [ ] BreakpointList
-- [ ] BreakpointGutter → `editor::EditorGutter`
-- [ ] CallStack
-- [ ] VariablesPanel
-- [ ] WatchPanel
-- [ ] ThreadList
-- [ ] MemoryViewer / HexViewer
-- [ ] Disassembly
-- [ ] PerformanceProfiler / Flamegraph
-- [ ] TimelineProfiler
-- [ ] NetworkInspector
-- [ ] ConsoleREPL → `editor::DebugConsole`
+- [x] DebugToolbar
+- [x] BreakpointList
+- [x] BreakpointGutter → `editor::CodeEditor`, its gutter and `toggle_breakpoint`
+- [x] CallStack
+- [x] VariablesPanel
+- [x] WatchPanel
+- [x] ThreadList
+- [x] MemoryViewer / HexViewer → `debug::HexViewer`, placed at `base`
+- [x] Disassembly
+- [x] PerformanceProfiler / Flamegraph → `debug::Flamegraph`
+- [x] TimelineProfiler
+- [x] NetworkInspector
+- [x] ConsoleREPL → `editor::DebugConsole`