Build first WaveMind Studio demo surface

[CaspianG]

Goal: create the first visual launch asset for WaveMind Studio / memory explorer.

The initial version should help people understand WaveMind in under a minute:

• namespace explorer;
• memory list with hotness/decay/TTL;
• query tester;
• clear stale-vs-current fact example;
• import/export or backup action;
• dark UI suitable for a short demo video or README GIF.

Acceptance criteria:

• runnable locally with one command;
• no external API key required;
• demo data included;
• screenshot or GIF added to the README/launch kit;
• implementation kept small enough to maintain.