move demo/ to docs/tutorial/, commit assets, consolidate TUI docs

- demo/ renamed to docs/tutorial/ (tapes, scripts, TUTORIAL.md)
- docs/tutorial/assets/ added to git (51 MB of GIFs + PNGs); removed
  /demo/assets/ from .gitignore so images render on Codeberg
- docs/tui-reference.md removed; its hotkey tables merged into a new
  "Hotkey Quick Reference" section at the end of TUTORIAL.md
- TUTORIAL.md: updated install section (mage buildDocker, no
  GOTOOLCHAIN=auto), fixed README relative path (../../README.md),
  updated internal tapes/scripts/assets path prose
- README.md: updated all demo/ image paths and links to docs/tutorial/;
  TUI and recording-modes links now point to TUTORIAL.md anchors
- AGENTS.md: updated demo/ references to docs/tutorial/
- Magefile.go: updated demoDir/demoTapesDir/demoScriptsDir/demoRunTape/
  demoSudoKeepers constants to docs/tutorial/ paths

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/docs/tutorial/scripts/sudo-keepalive.sh b/docs/tutorial/scripts/sudo-keepalive.sh
new file mode 100755
index 0000000..4ae1e27
--- /dev/null
+++ b/docs/tutorial/scripts/sudo-keepalive.sh
@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+# Refreshes the sudo timestamp every minute so a long demo regen never trips a
+# password prompt. Intended to be backgrounded by `mage demo` and killed at the
+# end of the run.
+
+set -u
+
+trap 'exit 0' TERM INT
+
+while true; do
+    sudo -n true 2>/dev/null || exit 1
+    sleep 60
+done