panel: readable everywhere, compact/full toggle, change-driven; jump shortcut

- contrast: the summary used attributed-string colors (never vibrant) and
  the subtitles a vibrant system color, so they blended differently over
  light and dark desktops. the panel now uses herdr's mocha colors
  explicitly over a dark tint, identical on any background.
- layout: compact in "when agents are waiting"; in "always" a show all /
  show less toggle switches to the full list (waiting, separator, rest).
- rows are single-line with a trailing ellipsis instead of wrapping.
- render only when the content changes, and log each render, instead of
  rebuilding every view every second.
- --snapshot-panel renders the real panel offscreen over white and black
  after a different first render (stale content would show).
- jump shortcut ctrl+opt+cmd+u (jump_hotkey) runs dingger focus; shortcuts
  are registered by id. an unedited first config file is upgraded.

selftest covers the layout rules and content; e2e step 13 checks the full
list, its separator, and the toggle labels.

1 files changed, 10 insertions, 6 deletions

diff --git a/README.md b/README.md
index c2a2a71..126dae3 100644
--- a/README.md
+++ b/README.md
@@ -44,10 +44,14 @@ than a poll is still a completion.
   (`◐ 2 working · ○ 15 idle`); click a row to jump there, drag to move it.
   **⌃⌥⌘E** shows or hides it from anywhere. Modes (menu bar, "Show Panel
   Automatically"): *When agents are waiting* (default; appears when
-  something is blocked or done, hides when you have attended to everything),
-  *Always*, *Off*. Hiding it with the shortcut lasts until another agent
-  starts waiting. Change the shortcut in `~/.config/dingger/config.toml`
-  (menu bar, Settings…); it reloads when you save.
+  something is blocked or done, hides when you have attended to everything;
+  compact), *Always* (with a "Show all / Show less" toggle for the full
+  list), *Off*. Hiding it with the shortcut lasts until another agent starts
+  waiting. The panel is always dark, in herdr's palette, so it reads the same
+  over any desktop.
+- **Jump shortcut**: **⌃⌥⌘U** jumps to the top waiting agent from anywhere,
+  like clicking the tmux status line. Both shortcuts live in
+  `~/.config/dingger/config.toml` (menu bar, Settings…), reloaded on save.
 - **tmux status line** (`packaging/tmux/dingger.tmux`): the same summary after
   the clock. Clicking it jumps to the top waiting agent (the menu's top row),
   skipping the window you already look at.
@@ -104,8 +108,8 @@ tests/e2e.sh         # end to end against an isolated tmux server
 30 s, so everything asserted must arrive through events), fake agents driven
 over the hook protocol, and a real tmux client whose focus it controls. It
 asserts every status transition, attendance by navigation, both click paths
-(including the real menu bar binary), the floating panel's visibility rules
-and content, the status-line segment, latency with a
+(including the real menu bar binary), the floating panel's visibility and
+layout rules and content (compact, full, toggle), the status-line segment, latency with a
 deliberately slow notifier, and state surviving a daemon restart. It never
 touches your tmux server.