docs: record demo GIF and embed in README

README.md

@@ -11,20 +11,9 @@
 
 </div>
 
----
-
-```text
-$ git commit -m "fix the auth flow"
-
-✗ gitswitch guard: blocked commit
-
-  in directory:   ~/work/some-repo/
-  expected:       you@company.com   (bound identity: work)
-  got:            you@gmail.com
-
-  fix:            gitswitch use work
-                  (or: git commit --no-verify to override this once)
-```
+<p align="center">
+  <img src="docs/demo.gif" alt="gitswitch guard blocking a wrong-author commit, then succeeding after fix" width="900">
+</p>
 
 ## The problem
 

docs/demo.tape

@@ -0,0 +1,94 @@
+# gitswitch — README demo recording.
+#
+# Run with:
+#   vhs docs/demo.tape
+#
+# Produces docs/demo.gif (embedded in the README) plus
+# docs/demo.mp4 (smaller, for Twitter / Show HN / LinkedIn).
+#
+# The tape is fully self-contained: it runs setup invisibly,
+# then records four scenes (state, commit attempt, blocked,
+# fixed + verified) in a sandbox $HOME so it never touches
+# the maintainer's real config or credentials.
+
+Output docs/demo.gif
+Output docs/demo.mp4
+
+Set FontSize 18
+Set Width 1100
+Set Height 700
+Set Theme "Catppuccin Mocha"
+Set TypingSpeed 60ms
+Set PlaybackSpeed 1.0
+Set Padding 24
+
+# ---------------------------------------------------------------
+# Hidden setup. Sandbox $HOME, seed two identities + bindings, set
+# up a work repo whose local user.email is deliberately wrong so
+# the next commit will trip the guard.
+# ---------------------------------------------------------------
+Hide
+Type `export HOME=/tmp/gitswitch-demo && rm -rf $HOME && mkdir -p $HOME/.config/gitswitch $HOME/.ssh /tmp/demo/work /tmp/demo/personal`
+Enter
+Type `printf '%s\n' '{"version":1,"identities":[{"name":"work","email":"you@company.com","git_name":"Work","ssh_key":"/tmp/demo/key","signing_key":"/tmp/demo/key.pub","gh_account":"you-work","vendor":"github"},{"name":"personal","email":"you@gmail.com","git_name":"Personal","ssh_key":"/tmp/demo/key","signing_key":"/tmp/demo/key.pub","gh_account":"you-personal","vendor":"github"}],"bindings":[{"directory":"/tmp/demo/work","identity":"work"},{"directory":"/tmp/demo/personal","identity":"personal"}]}' > $HOME/.config/gitswitch/config.json`
+Enter
+Type `gitswitch use work /tmp/demo/work > /dev/null 2>&1 && gitswitch use personal /tmp/demo/personal > /dev/null 2>&1 && gitswitch guard install > /dev/null 2>&1`
+Enter
+# The per-identity gitconfig that 'gitswitch use' just wrote turns on
+# SSH commit signing by default — but the sandbox SSH key is fake, so
+# real `git commit` would fail. Strip the signing/sshCommand bits for
+# the demo so the second-commit-succeeds frame actually succeeds.
+Type `for f in $HOME/.config/gitswitch/identities/*.gitconfig; do printf '[user]\nname = %s\nemail = %s\n' "$(grep -m1 '^    name' $f | sed 's/^    name = //')" "$(grep -m1 '^    email' $f | sed 's/^    email = //')" > $f; done`
+Enter
+Type `cd /tmp/demo/work && git init -q && git config user.email you@gmail.com && git config user.name "Personal" && echo "auth flow change" > handler.go && git add handler.go`
+Enter
+Type `PS1='$ '`
+Enter
+Sleep 200ms
+Ctrl+L
+Show
+
+# ---------------------------------------------------------------
+# Scene 1 — establish: the user has two identities configured.
+# ---------------------------------------------------------------
+Type "gitswitch list"
+Enter
+Sleep 3500ms
+
+# ---------------------------------------------------------------
+# Scene 2 — about to commit, looks normal.
+# ---------------------------------------------------------------
+Type "git status"
+Enter
+Sleep 2200ms
+
+Type "git commit -m 'fix the auth flow'"
+Enter
+
+# ---------------------------------------------------------------
+# Scene 3 — the marquee moment. Hold long enough for a viewer to
+# actually read the red panel.
+# ---------------------------------------------------------------
+Sleep 5500ms
+
+# ---------------------------------------------------------------
+# Scene 4 — the fix. Unset the local override so the includeIf
+# block from `gitswitch use` provides the right email; then retry.
+# ---------------------------------------------------------------
+Type "git config --unset user.email"
+Enter
+Sleep 1200ms
+
+Type "git commit -m 'fix the auth flow'"
+Enter
+Sleep 2500ms
+
+# ---------------------------------------------------------------
+# Scene 5 — victory lap. `why` confirms the active identity for
+# this directory. (Skipping `doctor` here because it depends on
+# real ssh-auth + gh — neither work in the sandbox; `why` works
+# entirely from local config.)
+# ---------------------------------------------------------------
+Type "gitswitch why"
+Enter
+Sleep 4500ms