docs(demo): AI demo procedure deck + fix graphify hook path separators

10-slide PPTX (docs/demo/AI_DEMO_SCRIPT.pptx): env/accounts, 4 demo
flows with concrete input examples (NL auto-layout phrases, ReRoom
sample photo at /downloads/demo/sample_booth.jpg, NL-query/rules-chat
questions), pre-demo checklist (Gemini paid-tier action item) and
fallback troubleshooting. Hook commands in .claude/settings.json now
use forward slashes - backslashes were eaten by the sh hook runner.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.claude/settings.json

@@ -6,7 +6,7 @@
         "hooks": [
           {
             "type": "command",
-            "command": "C:\\Users\\ython\\AppData\\Local\\Python\\pythoncore-3.14-64\\Scripts\\graphify.EXE hook-guard search"
+            "command": "C:/Users/ython/AppData/Local/Python/pythoncore-3.14-64/Scripts/graphify.EXE hook-guard search"
           }
         ]
       },
@@ -15,7 +15,7 @@
         "hooks": [
           {
             "type": "command",
-            "command": "C:\\Users\\ython\\AppData\\Local\\Python\\pythoncore-3.14-64\\Scripts\\graphify.EXE hook-guard read"
+            "command": "C:/Users/ython/AppData/Local/Python/pythoncore-3.14-64/Scripts/graphify.EXE hook-guard read"
           }
         ]
       }