v1.10.0 — Web UI: Diff Viewer, Session Manager, Slash Commands

Web UI Enhancements

• Diff Viewer — when files are written, replaced, or appended, the UI shows a line-level LCS diff (green + / red -) so you can see exactly what changed.
• Session Manager — create multiple sessions, switch between them, see auto-generated titles from the first message, model used, and message count.
• Slash Commands — type /active, /model 2, /safe, /allow, /reset, /models, /exit\ directly in the web input.
• Help Modal — click the ?\ button for a complete usage guide including model switching, commands reference, and diff viewer explanation.
• SSE streaming — uses \etch\ + \ReadableStream\ (no \EventSource\ dependency) for reliable streaming.

Server

• Diff events sent as SSE between \ ool_call\ and \ ool_result\ for \write_file,
  eplace_in_file, \�ppend_file\
• Session endpoints: \GET /api/sessions, \GET /api/sessions/:id\
• Session metadata tracking (auto-title, model label, message count, creation time)
• \sessions\ map exported for test access

Tests

• 137 unit tests passing (+8 new: session endpoints + diff event integration)