fix(spark-analytics): remove raw newline from webview JS comment

The SEP comment contained "\n\n", which Python's triple-quoted JS block
turned into real newline characters in the emitted script. That produced
an inline-<script> SyntaxError ("string literal contains an unescaped
line break"), so every handler went undefined and clicking the analyse
buttons did nothing (ReferenceError: analyzeRow is not defined).

Replace the comment text with plain words — no backslash escapes. Verified
by exec'ing serve.py (psycopg2 stubbed) to capture the Python-evaluated
JS and parsing it with node --check.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

spark-analytics/base/webview.yaml

@@ -209,7 +209,7 @@ data:
         }
         const reader = resp.body.getReader();
         const dec = new TextDecoder();
-        const SEP = String.fromCharCode(10, 10);  // "\n\n" — avoids YAML backslash escaping
+        const SEP = String.fromCharCode(10, 10);  // SSE frame separator (two newlines)
         let buf = '', full = '';
         for (;;) {
           const { done, value } = await reader.read();