Register the full grammar set the read tool's langFromPath emits (python,
go, rust, yaml, markdown, html, and the rest) so a read card highlights the
same extensions the backend recognizes instead of returning undefined for
them. Rewrite highlightLines' terminator-line check to the explicit
last !== undefined form to keep a single branch for per-file coverage.
Add the running-state sweep animation to ReadRow, matching BashRow/ToolRow,
so a running read row shows executing feedback.
Use file_path (the real read tool schema field) in the turn 66 read fixture
sample, its presentCall branch, and the turn 64 run_code read sub-dispatches,
so the built-boot snapshot replays a production-shaped call and the details
panel shows the correct Input JSON.
Document why ReadBlock omits TerminalBlock's empty-window copy guard, and
correct the read-card-model {@link} and the turn 66 fixture comment.
Chinesezjc
69a84e1403