fix: variables search bug and lite mode dataset seeding (#54)

* fix: remove non-existent label field from variables search

Variables don't have a label field, only name and description.
The search filter was referencing Variable.label which caused
500 errors when searching with tax_benefit_model_name filter.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

* feat: include datasets in lite mode, filter to 2026 only

- Lite mode now seeds FRS 2026 and CPS 2026 datasets instead of skipping all
- Added hugging_face_token setting for dataset downloads

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

* Update agent ui

* feat: improve agent chat UX and add conversation history

- Fix tool name display with proper mapping (e.g. "Calculate household")
- Add conversation history support for multi-turn chat
- Move response styling to global CSS with Inter font
- Add PolicyEngine style guide to agent prompt (tables, active voice)
- Persist tool steps per message so they don't disappear

---------

Co-authored-by: Claude <noreply@anthropic.com>

Author: nikhilwoodruff

docs/bun.lock

@@ -13,7 +13,8 @@
     "react": "19.2.1",
     "react-dom": "19.2.1",
     "react-markdown": "^10.1.0",
-    "remark-breaks": "^4.0.0"
+    "remark-breaks": "^4.0.0",
+    "remark-gfm": "^4.0.1"
   },
   "devDependencies": {
     "@tailwindcss/postcss": "^4",

docs/package.json

@@ -100,3 +100,125 @@ code {
   background: var(--color-pe-green);
   color: white;
 }
+
+/* Agent response content */
+.response-content {
+  font-family: var(--font-inter), -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
+  font-size: 15px;
+  line-height: 1.7;
+  color: #1e293b;
+  -webkit-font-smoothing: antialiased;
+}
+.response-content p {
+  margin: 0.875em 0;
+}
+.response-content p:first-child {
+  margin-top: 0;
+}
+.response-content p:last-child {
+  margin-bottom: 0;
+}
+.response-content h1,
+.response-content h2,
+.response-content h3 {
+  font-weight: 600;
+  color: #0f172a;
+  margin-top: 1.5em;
+  margin-bottom: 0.5em;
+  line-height: 1.3;
+}
+.response-content h1 {
+  font-size: 1.375em;
+}
+.response-content h2 {
+  font-size: 1.125em;
+}
+.response-content h3 {
+  font-size: 1em;
+}
+.response-content h1:first-child,
+.response-content h2:first-child,
+.response-content h3:first-child {
+  margin-top: 0;
+}
+.response-content strong {
+  font-weight: 600;
+  color: #0f172a;
+}
+.response-content ul,
+.response-content ol {
+  margin: 0.875em 0;
+  padding-left: 1.5em;
+}
+.response-content li {
+  margin: 0.375em 0;
+}
+.response-content li::marker {
+  color: #64748b;
+}
+.response-content code {
+  font-family: "JetBrains Mono", ui-monospace, monospace;
+  font-size: 0.875em;
+  background: #f1f5f9;
+  padding: 0.2em 0.4em;
+  border-radius: 4px;
+  color: #334155;
+}
+.response-content pre {
+  font-family: "JetBrains Mono", ui-monospace, monospace;
+  font-size: 13px;
+  background: #1e293b;
+  color: #e2e8f0;
+  padding: 1em 1.25em;
+  border-radius: 8px;
+  overflow-x: auto;
+  margin: 1em 0;
+  line-height: 1.6;
+}
+.response-content pre code {
+  background: none;
+  padding: 0;
+  font-size: inherit;
+  color: inherit;
+}
+.response-content table {
+  width: 100%;
+  border-collapse: collapse;
+  margin: 1em 0;
+  font-size: 14px;
+}
+.response-content th {
+  background: #f8fafc;
+  border: 1px solid #e2e8f0;
+  padding: 0.625em 0.875em;
+  text-align: left;
+  font-weight: 600;
+  color: #475569;
+}
+.response-content td {
+  border: 1px solid #e2e8f0;
+  padding: 0.625em 0.875em;
+  color: #334155;
+}
+.response-content tr:hover td {
+  background: #f8fafc;
+}
+.response-content blockquote {
+  border-left: 3px solid #2c6e49;
+  padding-left: 1em;
+  margin: 1em 0;
+  color: #64748b;
+  font-style: italic;
+}
+.response-content a {
+  color: #2c6e49;
+  text-decoration: underline;
+}
+.response-content a:hover {
+  color: #1a4a2e;
+}
+.response-content hr {
+  border: none;
+  border-top: 1px solid #e2e8f0;
+  margin: 1.5em 0;
+}