fix: add visualization quality guidance to agent system prompt

Add a "Visualization Quality Standards" section to steer the model
toward using Three.js (via import map) for 3D content instead of
CSS transform hacks or Canvas 2D projection. Documents available
ES module libraries (three, gsap, d3, chart.js), enforces
type="module" script tags, and sets a polished quality bar for
generated visualizations.

Author: GeneralJerel

apps/agent/main.py

@@ -53,6 +53,20 @@
         - Pre-styled form elements (buttons, inputs, sliders look native automatically)
         - Pre-built SVG CSS classes for color ramps (.c-purple, .c-teal, .c-blue, etc.)
 
+        ## Visualization Quality Standards
+
+        The iframe has an import map with these ES module libraries — use `<script type="module">` and bare import specifiers:
+        - `three` — 3D graphics. `import * as THREE from "three"`. Also `three/examples/jsm/controls/OrbitControls.js` for camera controls.
+        - `gsap` — animation. `import gsap from "gsap"`.
+        - `d3` — data visualization and force layouts. `import * as d3 from "d3"`.
+        - `chart.js/auto` — charts (but prefer the built-in `barChart`/`pieChart` components for simple charts).
+
+        **3D content**: ALWAYS use Three.js with proper WebGL rendering. Use real geometry, PBR materials (MeshStandardMaterial/MeshPhysicalMaterial), multiple light sources, and OrbitControls for interactivity. NEVER fake 3D with CSS transforms, CSS perspective, or Canvas 2D manual projection — these look broken and unprofessional.
+
+        **Quality bar**: Every visualization should look polished and portfolio-ready. Use smooth animations, proper lighting (ambient + directional at minimum), responsive canvas sizing (`window.addEventListener('resize', ...)`), and antialiasing (`antialias: true`). No proof-of-concept quality.
+
+        **Critical**: `<script type="module">` is REQUIRED when using import map libraries. Regular `<script>` tags cannot use `import` statements.
+
         ## UI Templates
 
         Users can save generated UIs as reusable templates and apply them later.