Add brand template generation scenario

[missbets]

Summary

• Adds a fifth scenario: Brand template generation — preserves the customer's PPT/Word template shapes, logos, formatting, and layout while filling placeholders from contextual inputs.
• Registers the scenario card on the landing page.
• Ships the contributed PPTWORDTemplateGenerator_1_0_0_2.zip solution zip and templatize_docx.py helper under sample/templates/.

Why

Existing "make me a deck" flows regenerate slides from scratch and lose brand fidelity. This scenario shows how ETC can chain a templatize step with contextual placeholder filling so the source file's shapes, logos, fonts, and layout stay untouched.

How it works

1. templatize_* walks the file, preserves brand elements, and replaces editable text with named placeholders.
2. The agent uses ETC to decide which placeholders need clarifying questions vs. tool calls vs. inference.
3. A fill step writes values back in place so the output preserves the original document design outside placeholder text.

Test plan

• npm run build succeeds
• New /scenarios/brand-template-generation/ route builds
• New card is registered on the home page
• Solution zip is included under sample/templates/

Notes

• Early Release wording follows the existing sample README language.

Credit

Contributed by Betty Le (Microsoft, Cloud Solution Architect).