Typing a slash — anywhere in the message, not just at the start — opens
an anchored typeahead listing matching commands and skills from
ClaudeConfig's slash list. Arrow keys move the selection, Enter/Tab
completes (inserting "/command "), Escape dismisses; with the popup
closed, Enter still submits and Tab still traverses. The recognition,
filtering, and completion are pure functions (slash_commands.dart) so
they're cheaply unit-tested; the overlay is a no-Material
CompositedTransformFollower keyed off the field's focus node.
T-152.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>