feat: initial CodeBoard monorepo scaffold

Turborepo monorepo with npm workspaces:
- apps/web: Next.js 14 frontend with Tailwind v4, SSE progress, doc viewer
- apps/worker: BullMQ job processor (clone → parse → LLM generate)
- packages/shared: TypeScript types
- packages/parser: Babel-based AST parser (JS/TS) + regex (Python)
- packages/llm: OpenAI/Anthropic provider abstraction + prompt pipeline
- packages/diagrams: Mermaid architecture & dependency graph generators
- packages/database: Prisma schema (PostgreSQL)
- Docker multi-stage build (web + worker targets)

All packages compile successfully with tsc and next build.

packages/llm/src/pipeline.ts

@@ -0,0 +1,153 @@
+import type { CodeStructure, GeneratedDocs, FileNode } from "@codeboard/shared";
+import type { LLMProvider } from "./providers/base.js";
+import { buildArchitecturePrompt } from "./prompts/architecture-overview.js";
+import { buildModuleSummaryPrompt } from "./prompts/module-summary.js";
+import { buildPatternsPrompt } from "./prompts/patterns-detection.js";
+import { buildGettingStartedPrompt } from "./prompts/getting-started.js";
+
+function parseSection(text: string, header: string): string {
+  const regex = new RegExp(`## ${header}\\s*\\n([\\s\\S]*?)(?=\\n## |$)`);
+  const match = regex.exec(text);
+  return match?.[1]?.trim() ?? "";
+}
+
+function parseMermaid(text: string): string {
+  const match = /```mermaid\s*\n([\s\S]*?)```/.exec(text);
+  return match?.[1]?.trim() ?? "flowchart TD\n  A[No diagram generated]";
+}
+
+function parseList(text: string): string[] {
+  return text
+    .split("\n")
+    .map((l) => l.replace(/^[-*]\s*/, "").trim())
+    .filter(Boolean);
+}
+
+export async function generateDocumentation(
+  codeStructure: CodeStructure,
+  provider: LLMProvider,
+  onProgress?: (stage: string, progress: number) => void
+): Promise<GeneratedDocs> {
+  onProgress?.("architecture", 10);
+
+  const archMessages = buildArchitecturePrompt(codeStructure);
+  const archResponse = await provider.chat(archMessages);
+
+  const architectureOverview = parseSection(archResponse, "Architecture Overview");
+  const techStackRaw = parseSection(archResponse, "Tech Stack");
+  const architectureDiagram = parseMermaid(archResponse);
+  const techStack = techStackRaw.split(",").map((s) => s.trim()).filter(Boolean);
+
+  onProgress?.("modules", 30);
+
+  const moduleLimit = Math.min(codeStructure.modules.length, 10);
+  const moduleSummaries = await Promise.all(
+    codeStructure.modules.slice(0, moduleLimit).map(async (mod) => {
+      const moduleFiles: FileNode[] = codeStructure.files.filter((f) =>
+        mod.files.includes(f.path)
+      );
+
+      if (moduleFiles.length === 0) {
+        return {
+          name: mod.name,
+          path: mod.path,
+          summary: "Empty module — no parseable files found.",
+          keyFiles: [],
+          publicApi: [],
+          dependsOn: [],
+          dependedBy: [],
+        };
+      }
+
+      const messages = buildModuleSummaryPrompt(mod, moduleFiles);
+      const response = await provider.chat(messages, { model: undefined });
+
+      const summary = parseSection(response, "Summary");
+      const keyFilesRaw = parseList(parseSection(response, "Key Files"));
+      const publicApi = parseList(parseSection(response, "Public API"));
+
+      const dependsOn = [
+        ...new Set(
+          moduleFiles.flatMap((f) =>
+            f.imports
+              .map((imp) => imp.source)
+              .filter((s) => !s.startsWith("."))
+          )
+        ),
+      ].slice(0, 10);
+
+      const dependedBy = codeStructure.dependencies
+        .filter((d) => mod.files.includes(d.target))
+        .map((d) => d.source)
+        .filter((s) => !mod.files.includes(s))
+        .slice(0, 10);
+
+      return {
+        name: mod.name,
+        path: mod.path,
+        summary: summary || "Module analyzed but no summary generated.",
+        keyFiles: keyFilesRaw.map((kf) => ({ path: kf, purpose: "" })),
+        publicApi,
+        dependsOn,
+        dependedBy,
+      };
+    })
+  );
+
+  onProgress?.("patterns", 60);
+
+  const patternsMessages = buildPatternsPrompt(codeStructure);
+  const patternsResponse = await provider.chat(patternsMessages);
+
+  const conventions = parseList(parseSection(patternsResponse, "Coding Conventions"));
+  const designPatterns = parseList(parseSection(patternsResponse, "Design Patterns"));
+  const architecturalDecisions = parseList(parseSection(patternsResponse, "Architectural Decisions"));
+
+  onProgress?.("getting-started", 80);
+
+  const gsMessages = buildGettingStartedPrompt(
+    codeStructure,
+    architectureOverview
+  );
+  const gsResponse = await provider.chat(gsMessages);
+
+  const prerequisites = parseList(parseSection(gsResponse, "Prerequisites"));
+  const setupSteps = parseList(parseSection(gsResponse, "Setup Steps"));
+  const firstTask = parseSection(gsResponse, "Your First Task");
+
+  onProgress?.("complete", 100);
+
+  const languages = [...new Set(codeStructure.files.map((f) => f.language))];
+
+  return {
+    id: "",
+    repoUrl: "",
+    repoName: "",
+    generatedAt: new Date().toISOString(),
+    sections: {
+      overview: {
+        title: "Architecture Overview",
+        description: architectureOverview,
+        architectureDiagram,
+        techStack,
+        keyMetrics: {
+          files: codeStructure.files.length,
+          modules: codeStructure.modules.length,
+          languages,
+        },
+      },
+      modules: moduleSummaries,
+      patterns: {
+        conventions,
+        designPatterns,
+        architecturalDecisions,
+      },
+      gettingStarted: {
+        prerequisites,
+        setupSteps,
+        firstTask,
+      },
+      dependencyGraph: architectureDiagram,
+    },
+  };
+}