chore(web): CI cleanup — declare debugLog global, fix entity-unescape order, drop v3 from UI branding

- Add debugLog to the /* global */ headers of the six JS files that call it
  (defined in base.html's first inline script) — resolves the wall of
  "'debugLog' is not defined" ESLint errors failing the Codacy check.
- Fix the two js/double-escaping CodeQL alerts in app-shell.js: the
  entity-unescape chains decoded & before </>, so a value
  containing a pre-escaped "&amp;lt;" wrongly double-decoded to "<".
  &amp; now decodes last (standard order). Pre-existing bug, made visible
  when the inline scripts moved into scannable .js files.
- Page title / header drop the "- v3" suffix, matching the de-versioned
  user-facing URL.

The remaining 7 CodeQL alerts are pre-existing patterns newly visible to
scanning (CodeQL doesn't see inline template JS): 4 github.com/htmx.org
URL-substring checks (the htmx ones match error-message text, not URLs —
false positives in context) and 1 innerHTML XSS-through-DOM in the GitHub
install flow. Triage/fix deferred to a focused follow-up rather than
expanding this PR.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KEZK1P1Q1fu5pcuVrkrCFZ

web_interface/static/v3/js/app-shell.js

@@ -1,3 +1,4 @@
+/* global debugLog */
 // SSE wiring + full Alpine app() implementation and tab logic
 // Extracted from templates/v3/base.html so browsers cache it as a static asset.
         // Assign to window so reconnectSSE() in app.js can reach them.
@@ -1480,9 +1481,9 @@
                                             unescapedValue = value
                                                 .replace(/"/g, '"')
                                                 .replace(/'/g, "'")
-                                                .replace(/&/g, '&')
                                                 .replace(/&lt;/g, '<')
-                                                .replace(/&gt;/g, '>');
+                                                .replace(/&gt;/g, '>')
+                                                .replace(/&amp;/g, '&');
                                         }
                                         
                                         // Try to parse as JSON
@@ -2253,9 +2254,9 @@
                                     unescapedValue = value
                                         .replace(/&quot;/g, '"')
                                         .replace(/&#39;/g, "'")
-                                        .replace(/&amp;/g, '&')
                                         .replace(/&lt;/g, '<')
-                                        .replace(/&gt;/g, '>');
+                                        .replace(/&gt;/g, '>')
+                                        .replace(/&amp;/g, '&');
                                 }
                                 
                                 try {