v0.7.1: Streaming + Markdown + URLs + Interrupt — TDD

Stream-chunk protocol: SSE streaming via provider-openai-stream,
cascade-stream with fboundp guard in think(). TUI renders live.

Stream interrupt: Esc during streaming marks [interrupted], finalizes msg.
SSE cancel infrastructure: *stream-cancel* check in read loop.

Markdown inline: **bold**, *italic*, `code` via parse-markdown-spans.
Code blocks: parse-markdown-blocks + syntax-highlight (keywords/strings/fns).
URL detection + Tab-to-activate: https:// URLs in dim, Tab opens.

Watchdog: 30s stall detection via Dexador read-timeout.
[streaming] indicator in status bar.

Pre-existing TUI test fixes (7): first→aref, nil→zerop, add-msg arg.

Core: 65/65  Neuro: 13/13  TUI View: 22/22  TUI Main: 65/65
Total: 165 tests, 0 failures.

org/core-transport.org

@@ -151,7 +151,7 @@ The daemon sends a handshake message on connection, then enters a read loop, inj
   (let ((stream (usocket:socket-stream socket)))
     (handler-case
         (progn
-          (format stream "~a" (frame-message (make-hello-message "0.5.0")))
+          (format stream "~a" (frame-message (make-hello-message "0.7.1")))
           (finish-output stream)
           (loop
             (let ((msg (read-framed-message stream)))