Fix dev backend startup: use python -m uvicorn instead of uv run

uv pip install --system installs packages globally but uv run still
tries to create /app/.venv, which fails with permission denied.
Add PYTHONPATH=/app/src since the editable install .pth file is empty
when built without source directory present.

backend/src/spicebook/models/notebook.py

@@ -47,6 +47,8 @@ class NotebookSummary(BaseModel):
     tags: list[str]
     cell_count: int
     modified: str
+    description: str | None = None
+    schematic_svg: str | None = None
 
 
 class CreateNotebookRequest(BaseModel):

backend/src/spicebook/storage/filesystem.py

@@ -51,6 +51,44 @@ def _notebook_id_from_path(path: Path) -> str:
     return path.stem
 
 
+def _extract_card_data(nb: Notebook) -> tuple[str | None, str | None]:
+    """Extract a description snippet and schematic SVG from notebook cells.
+
+    - description: text from the first markdown cell, with the title header
+      stripped and truncated to ~200 characters.
+    - schematic_svg: SVG string from the first successful schematic output.
+    """
+    description: str | None = None
+    schematic_svg: str | None = None
+
+    for cell in nb.cells:
+        if description is None and cell.type == CellType.MARKDOWN and cell.source.strip():
+            lines = cell.source.strip().splitlines()
+            # Strip leading "# Title" header line
+            if lines and lines[0].lstrip().startswith("#"):
+                lines = lines[1:]
+            text = " ".join(line.strip() for line in lines if line.strip())
+            # Strip basic markdown syntax
+            text = re.sub(r"[*_`~\[\]#>]", "", text).strip()
+            if text:
+                description = text[:200].rstrip()
+
+        if schematic_svg is None:
+            for output in cell.outputs:
+                if (
+                    output.output_type == "schematic"
+                    and output.data.get("success")
+                    and output.data.get("svg")
+                ):
+                    schematic_svg = output.data["svg"]
+                    break
+
+        if description is not None and schematic_svg is not None:
+            break
+
+    return description, schematic_svg
+
+
 def list_notebooks(directory: Path) -> list[NotebookSummary]:
     """List all notebooks in the directory and its examples/ subdirectory."""
     summaries: list[NotebookSummary] = []
@@ -66,6 +104,7 @@ def list_notebooks(directory: Path) -> list[NotebookSummary]:
 
             try:
                 nb = _read_notebook_file(path)
+                description, schematic_svg = _extract_card_data(nb)
                 summaries.append(NotebookSummary(
                     id=nb_id,
                     title=nb.metadata.title,
@@ -73,6 +112,8 @@ def list_notebooks(directory: Path) -> list[NotebookSummary]:
                     tags=nb.metadata.tags,
                     cell_count=len(nb.cells),
                     modified=nb.metadata.modified,
+                    description=description,
+                    schematic_svg=schematic_svg,
                 ))
             except Exception:
                 logger.warning("Skipping corrupt notebook: %s", path)

docker-compose.dev.yml

@@ -4,23 +4,50 @@ services:
       context: ./backend
       dockerfile: Dockerfile
       target: dev
-    ports:
+    expose:
-      - "${BACKEND_PORT:-8099}:8000"
+      - "8000"
     volumes:
       - ./backend/src:/app/src
       - ./notebooks:/app/notebooks
       # Mount mcltspice for live development
       - ../mcp-ltspice/src/mcltspice:/app/mcltspice-lib:ro
-    command: ["uv", "run", "uvicorn", "spicebook.main:app", "--host", "0.0.0.0", "--port", "8000", "--reload"]
+    environment:
+      - PYTHONPATH=/app/src
+    command: ["python", "-m", "uvicorn", "spicebook.main:app", "--host", "0.0.0.0", "--port", "8000", "--reload"]
+    networks:
+      - default
+      - caddy
+    labels:
+      caddy: "${SPICEBOOK_DOMAIN:-spicebook.localhost}"
+      caddy.@api.path: "/api/* /health /docs /openapi.json /redoc"
+      caddy.reverse_proxy_0: "@api {{upstreams 8000}}"
 
   frontend:
     build:
       context: ./frontend
       dockerfile: Dockerfile
       target: dev
-    ports:
+    expose:
-      - "${FRONTEND_PORT:-4321}:4321"
+      - "4321"
     volumes:
       - ./frontend/src:/app/src
       - ./frontend/public:/app/public
     command: ["npm", "run", "dev", "--", "--host", "0.0.0.0"]
+    networks:
+      - default
+      - caddy
+    labels:
+      caddy: "${SPICEBOOK_DOMAIN:-spicebook.localhost}"
+      caddy.reverse_proxy_1: "{{upstreams 4321}}"
+      caddy.reverse_proxy_1.flush_interval: "-1"
+      caddy.reverse_proxy_1.transport: "http"
+      caddy.reverse_proxy_1.transport.read_timeout: "0"
+      caddy.reverse_proxy_1.transport.write_timeout: "0"
+      caddy.reverse_proxy_1.transport.keepalive: "5m"
+      caddy.reverse_proxy_1.transport.keepalive_idle_conns: "10"
+      caddy.reverse_proxy_1.stream_timeout: "24h"
+      caddy.reverse_proxy_1.stream_close_delay: "5s"
+
+networks:
+  caddy:
+    external: true

frontend/src/components/NotebookCard.tsx

@@ -25,14 +25,21 @@ interface NotebookCardProps {
 }
 
 export function NotebookCard({ notebook }: NotebookCardProps) {
-  const { id, title, engine, tags, cell_count, modified } = notebook;
+  const { id, title, engine, tags, cell_count, modified, description, schematic_svg } = notebook;
 
   return (
     <a
       href={`/notebook/${encodeURIComponent(id)}`}
       className="group block rounded-lg border border-slate-800 bg-slate-900/50 overflow-hidden hover:border-blue-500/40 hover:bg-slate-800/70 transition-all"
     >
-      <div className="notebook-card-strip" data-engine={engine} />
+      {schematic_svg ? (
+        <div
+          className="w-full h-[120px] bg-[#f8faf6] border-b border-slate-800/60 overflow-hidden flex items-center justify-center [&_svg]:max-w-full [&_svg]:max-h-full [&_svg]:w-auto [&_svg]:h-auto"
+          dangerouslySetInnerHTML={{ __html: schematic_svg }}
+        />
+      ) : (
+        <div className="notebook-card-strip" data-engine={engine} />
+      )}
       <div className="p-5">
         <div className="flex items-start justify-between mb-2">
           <h3 className="text-base font-semibold text-slate-100 group-hover:text-blue-400 transition-colors line-clamp-1">
@@ -43,6 +50,12 @@ export function NotebookCard({ notebook }: NotebookCardProps) {
           </Badge>
         </div>
 
+        {description && (
+          <p className="text-sm text-slate-400 leading-relaxed mb-2 line-clamp-2">
+            {description}
+          </p>
+        )}
+
         <div className="flex items-center gap-3 text-xs text-slate-500 mb-3">
           <span className="inline-flex items-center gap-1">
             <LayoutGrid className="w-3 h-3" />

frontend/src/components/ResistorColorGuide.astro

@@ -0,0 +1,199 @@
+---
+/**
+ * Resistor Color Code Guide — educational reference section.
+ *
+ * Left column: annotated SVG showing a 10k resistor zigzag with labeled bands.
+ * Right column: compact reference table mapping colors to digits and multipliers.
+ *
+ * Colors match BAND_HEX from resistor_colors.py so dots match schematic rendering.
+ */
+
+// BAND_HEX values from backend/src/spicebook/engine/resistor_colors.py
+const bandHex: Record<string, string> = {
+  black:  '#1a1a1a',
+  brown:  '#8B4513',
+  red:    '#CC0000',
+  orange: '#E67300',
+  yellow: '#B8960B',
+  green:  '#006400',
+  blue:   '#0000CC',
+  violet: '#7B00B3',
+  gray:   '#666666',
+  white:  '#D0D0D0',
+  gold:   '#B8860B',
+  silver: '#808080',
+};
+
+const digitBands = [
+  { color: 'Black',  hex: bandHex.black,  digit: 0, multiplier: '×1 \u03A9' },
+  { color: 'Brown',  hex: bandHex.brown,  digit: 1, multiplier: '×10 \u03A9' },
+  { color: 'Red',    hex: bandHex.red,    digit: 2, multiplier: '×100 \u03A9' },
+  { color: 'Orange', hex: bandHex.orange, digit: 3, multiplier: '×1 k\u03A9' },
+  { color: 'Yellow', hex: bandHex.yellow, digit: 4, multiplier: '×10 k\u03A9' },
+  { color: 'Green',  hex: bandHex.green,  digit: 5, multiplier: '×100 k\u03A9' },
+  { color: 'Blue',   hex: bandHex.blue,   digit: 6, multiplier: '×1 M\u03A9' },
+  { color: 'Violet', hex: bandHex.violet, digit: 7, multiplier: '×10 M\u03A9' },
+  { color: 'Gray',   hex: bandHex.gray,   digit: 8, multiplier: '\u2014' },
+  { color: 'White',  hex: bandHex.white,  digit: 9, multiplier: '\u2014' },
+];
+
+const toleranceBands = [
+  { color: 'Gold',   hex: bandHex.gold,   value: '\u00B15%' },
+  { color: 'Silver', hex: bandHex.silver, value: '\u00B110%' },
+];
+---
+
+<section class="max-w-6xl mx-auto px-6 py-16">
+  <p class="text-sm font-semibold tracking-widest text-blue-400 uppercase mb-2">Reference</p>
+  <h2 class="text-2xl font-bold text-slate-100 mb-3">Reading Resistor Color Codes</h2>
+  <p class="text-sm text-slate-400 mb-8 max-w-2xl leading-relaxed">
+    Resistors in SpiceBook schematics use color-coded bands — the same EIA standard
+    printed on physical components. Each colored segment of the zigzag symbol encodes
+    a digit, multiplier, or tolerance value.
+  </p>
+
+  <div class="grid gap-8 lg:grid-cols-[1fr_1fr] items-start">
+
+    <!-- Left: Annotated resistor diagram -->
+    <div class="rcg-diagram-card">
+      <svg viewBox="0 0 460 200" xmlns="http://www.w3.org/2000/svg" class="w-full h-auto" aria-label="Annotated 10k ohm resistor showing 4 color bands">
+
+        <!-- Mims graph paper background -->
+        <defs>
+          <pattern id="rcg-minor" width="10" height="10" patternUnits="userSpaceOnUse">
+            <path d="M 10 0 V 10 H 0" fill="none" stroke="#d4e4d4" stroke-width="0.3"/>
+          </pattern>
+          <pattern id="rcg-major" width="50" height="50" patternUnits="userSpaceOnUse">
+            <path d="M 50 0 V 50 H 0" fill="none" stroke="#b0ccb0" stroke-width="0.5"/>
+          </pattern>
+        </defs>
+        <rect width="460" height="200" fill="#f8faf6" rx="4"/>
+        <rect width="460" height="200" fill="url(#rcg-minor)" rx="4"/>
+        <rect width="460" height="200" fill="url(#rcg-major)" rx="4"/>
+
+        <!-- Lead wires -->
+        <line x1="40" y1="100" x2="100" y2="100" stroke="#555" stroke-width="2"/>
+        <line x1="360" y1="100" x2="420" y2="100" stroke="#555" stroke-width="2"/>
+
+        <!-- Zigzag body — 7 segments like backend mapping -->
+        <!-- seg 0: entry half-rise (wire) -->
+        <polyline points="100,100 120,72" fill="none" stroke="#555" stroke-width="2.5" stroke-linecap="round" stroke-linejoin="round"/>
+        <!-- seg 1: Band 1 - Brown (1st digit = 1) -->
+        <polyline points="120,72 160,128" fill="none" stroke={bandHex.brown} stroke-width="3" stroke-linecap="round" stroke-linejoin="round"/>
+        <!-- seg 2: Band 2 - Black (2nd digit = 0) -->
+        <polyline points="160,128 200,72" fill="none" stroke={bandHex.black} stroke-width="3" stroke-linecap="round" stroke-linejoin="round"/>
+        <!-- seg 3: Band 3 - Orange (multiplier = ×1kΩ) -->
+        <polyline points="200,72 240,128" fill="none" stroke={bandHex.orange} stroke-width="3" stroke-linecap="round" stroke-linejoin="round"/>
+        <!-- seg 4: gap (wire) -->
+        <polyline points="240,128 280,72" fill="none" stroke="#555" stroke-width="2.5" stroke-linecap="round" stroke-linejoin="round"/>
+        <!-- seg 5: Band 4 - Gold (tolerance = ±5%) -->
+        <polyline points="280,72 320,128" fill="none" stroke={bandHex.gold} stroke-width="3" stroke-linecap="round" stroke-linejoin="round"/>
+        <!-- seg 6: exit half-rise (wire) -->
+        <polyline points="320,128 340,100" fill="none" stroke="#555" stroke-width="2.5" stroke-linecap="round" stroke-linejoin="round"/>
+
+        <!-- Lead wire continuation -->
+        <line x1="340" y1="100" x2="360" y2="100" stroke="#555" stroke-width="2"/>
+
+        <!-- Callout labels with lines -->
+        <!-- Band 1: Brown -->
+        <line x1="140" y1="68" x2="140" y2="36" stroke="#888" stroke-width="0.8" stroke-dasharray="2,2"/>
+        <text x="140" y="30" text-anchor="middle" font-family="ui-monospace, monospace" font-size="10" fill="#555" font-weight="600">1st digit</text>
+        <text x="140" y="18" text-anchor="middle" font-family="ui-monospace, monospace" font-size="8.5" fill={bandHex.brown}>Brown = 1</text>
+
+        <!-- Band 2: Black -->
+        <line x1="180" y1="132" x2="180" y2="164" stroke="#888" stroke-width="0.8" stroke-dasharray="2,2"/>
+        <text x="180" y="175" text-anchor="middle" font-family="ui-monospace, monospace" font-size="10" fill="#555" font-weight="600">2nd digit</text>
+        <text x="180" y="188" text-anchor="middle" font-family="ui-monospace, monospace" font-size="8.5" fill="#444">Black = 0</text>
+
+        <!-- Band 3: Orange -->
+        <line x1="220" y1="68" x2="220" y2="36" stroke="#888" stroke-width="0.8" stroke-dasharray="2,2"/>
+        <text x="220" y="30" text-anchor="middle" font-family="ui-monospace, monospace" font-size="10" fill="#555" font-weight="600">Multiplier</text>
+        <text x="220" y="18" text-anchor="middle" font-family="ui-monospace, monospace" font-size="8.5" fill={bandHex.orange}>Orange = ×1k&#937;</text>
+
+        <!-- Band 4: Gold -->
+        <line x1="300" y1="132" x2="300" y2="164" stroke="#888" stroke-width="0.8" stroke-dasharray="2,2"/>
+        <text x="300" y="175" text-anchor="middle" font-family="ui-monospace, monospace" font-size="10" fill="#555" font-weight="600">Tolerance</text>
+        <text x="300" y="188" text-anchor="middle" font-family="ui-monospace, monospace" font-size="8.5" fill={bandHex.gold}>Gold = ±5%</text>
+
+        <!-- Result value label -->
+        <rect x="360" y="58" width="90" height="24" rx="3" fill="#f0f2ee" stroke="#b0ccb0" stroke-width="0.8"/>
+        <text x="405" y="74" text-anchor="middle" font-family="ui-monospace, monospace" font-size="11" fill="#333" font-weight="700">10 k&#937; ±5%</text>
+      </svg>
+    </div>
+
+    <!-- Right: Color code reference table -->
+    <div class="rcg-table-card">
+      <table class="w-full text-sm">
+        <thead>
+          <tr class="border-b border-slate-700/60">
+            <th class="rcg-th text-left py-2.5 pr-2">Color</th>
+            <th class="rcg-th text-center py-2.5 px-2">Digit</th>
+            <th class="rcg-th text-left py-2.5 pl-2">Multiplier</th>
+          </tr>
+        </thead>
+        <tbody>
+          {digitBands.map((band) => (
+            <tr class="border-b border-slate-800/40">
+              <td class="py-1.5 pr-2">
+                <span class="inline-flex items-center gap-2">
+                  <span class="rcg-dot" style={`background: ${band.hex};`}></span>
+                  <span class="text-slate-300 text-xs">{band.color}</span>
+                </span>
+              </td>
+              <td class="text-center py-1.5 px-2 text-slate-300 font-mono text-xs">{band.digit}</td>
+              <td class="py-1.5 pl-2 text-slate-400 font-mono text-xs">{band.multiplier}</td>
+            </tr>
+          ))}
+        </tbody>
+      </table>
+
+      <!-- Tolerance row -->
+      <div class="mt-4 pt-3 border-t border-slate-700/60">
+        <p class="text-xs font-semibold text-slate-500 uppercase tracking-wider mb-2">Tolerance</p>
+        <div class="flex gap-6">
+          {toleranceBands.map((band) => (
+            <span class="inline-flex items-center gap-2">
+              <span class="rcg-dot" style={`background: ${band.hex};`}></span>
+              <span class="text-slate-300 text-xs">{band.color}</span>
+              <span class="text-slate-400 font-mono text-xs">{band.value}</span>
+            </span>
+          ))}
+        </div>
+      </div>
+    </div>
+
+  </div>
+</section>
+
+<style>
+  .rcg-diagram-card {
+    border-radius: 0.5rem;
+    border: 1px solid #1e293b;
+    overflow: hidden;
+    background: #f8faf6;
+  }
+
+  .rcg-table-card {
+    border-radius: 0.5rem;
+    border: 1px solid #1e293b;
+    background: rgba(15, 23, 42, 0.5);
+    padding: 1.25rem;
+  }
+
+  .rcg-th {
+    font-size: 0.7rem;
+    font-weight: 600;
+    text-transform: uppercase;
+    letter-spacing: 0.06em;
+    color: #64748b;
+  }
+
+  .rcg-dot {
+    display: inline-block;
+    width: 10px;
+    height: 10px;
+    border-radius: 50%;
+    flex-shrink: 0;
+    border: 1px solid rgba(148, 163, 184, 0.2);
+  }
+</style>

frontend/src/lib/types.ts

@@ -34,6 +34,8 @@ export interface NotebookSummary {
   tags: string[];
   cell_count: number;
   modified: string;
+  description?: string;
+  schematic_svg?: string;
 }
 
 export interface WaveformVariable {

frontend/src/pages/index.astro

@@ -3,6 +3,7 @@ import { Icon } from 'astro-icon/components';
 import NotebookLayout from '../layouts/NotebookLayout.astro';
 import NotebookGallery from '../components/NotebookGallery';
 import PipelineStrip from '../components/PipelineStrip.astro';
+import ResistorColorGuide from '../components/ResistorColorGuide.astro';
 import FeaturedNotebooks from '../components/FeaturedNotebooks.astro';
 import OscilloscopeDisplay from '../components/OscilloscopeDisplay.astro';
 import { fetchNotebookList } from '../lib/server-api';
@@ -72,6 +73,11 @@ try {
     <PipelineStrip />
   </section>
 
+  <!-- Resistor Color Code Guide -->
+  <section class="border-b border-slate-800/60">
+    <ResistorColorGuide />
+  </section>
+
   <!-- Featured Notebooks -->
   <section class="border-b border-slate-800/60">
     <FeaturedNotebooks />