Initial commit: LangChain evolution tutorial deck (132 slides)

- Cover, TOC, 5 dividers, 3 recap slides
- 5 sections (chains, langgraph, deepagents, openswe, ecosystem)
- design-system.js with theme tokens + 9 helper functions
- research/: timeline + sources + per-tech notes
- final-compile.js + merge.js for rebuild pipeline
- output/: langchain-evolution.pptx (2.3 MB) + langchain-evolution.pdf (1.1 MB) + 7 sample previews

slides/section5-ecosystem/slide-12.js

@@ -0,0 +1,66 @@
+// Slide 12: TypeScript SDK + final ecosystem pros/cons
+// Two-column: code on left, pros/cons on right.
+
+const ds = require('./design-system');
+
+function createSlide(pres, theme) {
+  const slide = pres.addSlide();
+  ds.helpers.slideBase(slide, pres, theme);
+
+  ds.helpers.addHeader(slide, pres, theme, {
+    eyebrow: 'STAGE 5: ECOSYSTEM',
+    section: 'Итоги',
+    title: 'TypeScript SDK и плюсы/минусы',
+    sectionNumber: 5,
+    titleSize: 24,
+  });
+
+  // Left code block -- TypeScript SDK
+  ds.helpers.addCodeBlock(slide, pres, theme, {
+    x: 0.5, y: 1.45, w: 5.5, h: 3.1,
+    language: 'typescript',
+    fontSize: 10,
+    code: [
+      'import { Client, traceable } from "langsmith";',
+      '',
+      'const client = new Client();',
+      '',
+      '// @traceable decorator -- точно как в Python',
+      'const retrieve = traceable(',
+      '  async function retrieve(query: string) {',
+      '    return vectorStore.similaritySearch(query, 4);',
+      '  },',
+      '  { name: "retrieve_docs", runType: "retriever" }',
+      ');',
+      '',
+      '// run_on_dataset для eval -- тоже есть',
+      'await client.runOnDataset(',
+      '  "rag-qa-eval-v1", target,',
+      '  { evaluators: [answerMatch] }',
+      ');',
+    ].join('\n'),
+  });
+
+  // Right pros/cons panel
+  ds.helpers.addProsCons(slide, pres, theme, {
+    x: 6.2, y: 1.45, w: 3.3, h: 3.1,
+    pros: [
+      'Auto-tracing из коробки',
+      'Eval = CI/CD для промптов',
+      'Platform = deploy за минуты',
+      'Self-hosted опция',
+    ],
+    cons: [
+      'LangSmith SDK 0.x',
+      'Cloud растет в цене',
+      'Self-hosted требует K8s',
+    ],
+  });
+
+  ds.helpers.addSourceLine(slide, pres, theme, {
+    source: 'github.com/langchain-ai/langsmith-sdk + langgraph-sdk README',
+  });
+  ds.helpers.addPageNumber(slide, pres, theme, 12);
+}
+
+module.exports = { createSlide };