Merge branch 'develop' into feature/know-link-resolution

apps/api/src/app.module.ts

@@ -15,7 +15,7 @@ import { LayoutsModule } from "./layouts/layouts.module";
 import { KnowledgeModule } from "./knowledge/knowledge.module";
 import { UsersModule } from "./users/users.module";
 import { WebSocketModule } from "./websocket/websocket.module";
-import { OllamaModule } from "./ollama/ollama.module";
+import { LlmModule } from "./llm/llm.module";
 
 @Module({
   imports: [
@@ -33,7 +33,7 @@ import { OllamaModule } from "./ollama/ollama.module";
     KnowledgeModule,
     UsersModule,
     WebSocketModule,
-    OllamaModule,
+    LlmModule,
   ],
   controllers: [AppController],
   providers: [AppService],

apps/api/src/llm/dto/chat.dto.ts

@@ -0,0 +1,7 @@
+import { IsArray, IsString, IsOptional, IsBoolean, IsNumber, ValidateNested, IsIn } from "class-validator";
+import { Type } from "class-transformer";
+export type ChatRole = "system" | "user" | "assistant";
+export class ChatMessageDto { @IsString() @IsIn(["system", "user", "assistant"]) role!: ChatRole; @IsString() content!: string; }
+export class ChatRequestDto { @IsString() model!: string; @IsArray() @ValidateNested({ each: true }) @Type(() => ChatMessageDto) messages!: ChatMessageDto[]; @IsOptional() @IsBoolean() stream?: boolean; @IsOptional() @IsNumber() temperature?: number; @IsOptional() @IsNumber() maxTokens?: number; @IsOptional() @IsString() systemPrompt?: string; }
+export interface ChatResponseDto { model: string; message: { role: ChatRole; content: string }; done: boolean; totalDuration?: number; promptEvalCount?: number; evalCount?: number; }
+export interface ChatStreamChunkDto { model: string; message: { role: ChatRole; content: string }; done: boolean; }

apps/api/src/llm/dto/embed.dto.ts

@@ -0,0 +1,3 @@
+import { IsArray, IsString, IsOptional } from "class-validator";
+export class EmbedRequestDto { @IsString() model!: string; @IsArray() @IsString({ each: true }) input!: string[]; @IsOptional() @IsString() truncate?: "start" | "end" | "none"; }
+export interface EmbedResponseDto { model: string; embeddings: number[][]; totalDuration?: number; }

apps/api/src/llm/dto/index.ts

@@ -0,0 +1,2 @@
+export * from "./chat.dto";
+export * from "./embed.dto";

apps/api/src/llm/index.ts

@@ -0,0 +1,4 @@
+export * from "./llm.module";
+export * from "./llm.service";
+export * from "./llm.controller";
+export * from "./dto";

apps/api/src/llm/llm.controller.spec.ts

@@ -0,0 +1,15 @@
+import { describe, it, expect, beforeEach, vi } from "vitest";
+import { Test, TestingModule } from "@nestjs/testing";
+import { LlmController } from "./llm.controller";
+import { LlmService } from "./llm.service";
+import type { ChatRequestDto, EmbedRequestDto } from "./dto";
+describe("LlmController", () => {
+  let controller: LlmController;
+  const mockService = { checkHealth: vi.fn(), listModels: vi.fn(), chat: vi.fn(), chatStream: vi.fn(), embed: vi.fn() };
+  beforeEach(async () => { vi.clearAllMocks(); controller = (await Test.createTestingModule({ controllers: [LlmController], providers: [{ provide: LlmService, useValue: mockService }] }).compile()).get(LlmController); });
+  it("should be defined", () => { expect(controller).toBeDefined(); });
+  describe("health", () => { it("should return status", async () => { const s = { healthy: true, host: "h" }; mockService.checkHealth.mockResolvedValue(s); expect(await controller.health()).toEqual(s); }); });
+  describe("listModels", () => { it("should return models", async () => { mockService.listModels.mockResolvedValue(["m1"]); expect(await controller.listModels()).toEqual({ models: ["m1"] }); }); });
+  describe("chat", () => { const req: ChatRequestDto = { model: "m", messages: [{ role: "user", content: "x" }] }; const res = { setHeader: vi.fn(), write: vi.fn(), end: vi.fn() }; it("should return response", async () => { const r = { model: "m", message: { role: "assistant", content: "y" }, done: true }; mockService.chat.mockResolvedValue(r); expect(await controller.chat(req, res as any)).toEqual(r); }); it("should stream", async () => { mockService.chatStream.mockReturnValue((async function* () { yield { model: "m", message: { role: "a", content: "x" }, done: true }; })()); await controller.chat({ ...req, stream: true }, res as any); expect(res.setHeader).toHaveBeenCalled(); expect(res.end).toHaveBeenCalled(); }); });
+  describe("embed", () => { it("should return embeddings", async () => { const r = { model: "m", embeddings: [[0.1]] }; mockService.embed.mockResolvedValue(r); expect(await controller.embed({ model: "m", input: ["x"] })).toEqual(r); }); });
+});

apps/api/src/llm/llm.controller.ts

@@ -0,0 +1,12 @@
+import { Controller, Post, Get, Body, Res, HttpCode, HttpStatus } from "@nestjs/common";
+import { Response } from "express";
+import { LlmService, OllamaHealthStatus } from "./llm.service";
+import { ChatRequestDto, ChatResponseDto, EmbedRequestDto, EmbedResponseDto } from "./dto";
+@Controller("llm")
+export class LlmController {
+  constructor(private readonly llmService: LlmService) {}
+  @Get("health") async health(): Promise<OllamaHealthStatus> { return this.llmService.checkHealth(); }
+  @Get("models") async listModels(): Promise<{ models: string[] }> { return { models: await this.llmService.listModels() }; }
+  @Post("chat") @HttpCode(HttpStatus.OK) async chat(@Body() req: ChatRequestDto, @Res({ passthrough: true }) res: Response): Promise<ChatResponseDto | void> { if (req.stream === true) { res.setHeader("Content-Type", "text/event-stream"); res.setHeader("Cache-Control", "no-cache"); res.setHeader("Connection", "keep-alive"); res.setHeader("X-Accel-Buffering", "no"); try { for await (const c of this.llmService.chatStream(req)) res.write("data: " + JSON.stringify(c) + "\n\n"); res.write("data: [DONE]\n\n"); res.end(); } catch (e: unknown) { res.write("data: " + JSON.stringify({ error: e instanceof Error ? e.message : String(e) }) + "\n\n"); res.end(); } return; } return this.llmService.chat(req); }
+  @Post("embed") @HttpCode(HttpStatus.OK) async embed(@Body() req: EmbedRequestDto): Promise<EmbedResponseDto> { return this.llmService.embed(req); }
+}

apps/api/src/llm/llm.module.ts

@@ -0,0 +1,5 @@
+import { Module } from "@nestjs/common";
+import { LlmController } from "./llm.controller";
+import { LlmService } from "./llm.service";
+@Module({ controllers: [LlmController], providers: [LlmService], exports: [LlmService] })
+export class LlmModule {}

apps/api/src/llm/llm.service.spec.ts

@@ -0,0 +1,19 @@
+import { describe, it, expect, beforeEach, vi, afterEach } from "vitest";
+import { Test, TestingModule } from "@nestjs/testing";
+import { ServiceUnavailableException } from "@nestjs/common";
+import { LlmService } from "./llm.service";
+import type { ChatRequestDto, EmbedRequestDto } from "./dto";
+const mockList = vi.fn(); const mockChat = vi.fn(); const mockEmbed = vi.fn();
+vi.mock("ollama", () => ({ Ollama: class { list = mockList; chat = mockChat; embed = mockEmbed; } }));
+describe("LlmService", () => {
+  let service: LlmService;
+  const originalEnv = { ...process.env };
+  beforeEach(async () => { process.env = { ...originalEnv, OLLAMA_HOST: "http://test:11434", OLLAMA_TIMEOUT: "60000" }; vi.clearAllMocks(); service = (await Test.createTestingModule({ providers: [LlmService] }).compile()).get(LlmService); });
+  afterEach(() => { process.env = originalEnv; });
+  it("should be defined", () => { expect(service).toBeDefined(); });
+  describe("checkHealth", () => { it("should return healthy", async () => { mockList.mockResolvedValue({ models: [{ name: "llama3.2" }] }); const r = await service.checkHealth(); expect(r.healthy).toBe(true); }); it("should return unhealthy on error", async () => { mockList.mockRejectedValue(new Error("fail")); const r = await service.checkHealth(); expect(r.healthy).toBe(false); }); });
+  describe("listModels", () => { it("should return models", async () => { mockList.mockResolvedValue({ models: [{ name: "llama3.2" }] }); expect(await service.listModels()).toEqual(["llama3.2"]); }); it("should throw on error", async () => { mockList.mockRejectedValue(new Error("fail")); await expect(service.listModels()).rejects.toThrow(ServiceUnavailableException); }); });
+  describe("chat", () => { const req: ChatRequestDto = { model: "llama3.2", messages: [{ role: "user", content: "Hi" }] }; it("should return response", async () => { mockChat.mockResolvedValue({ model: "llama3.2", message: { role: "assistant", content: "Hello" }, done: true }); const r = await service.chat(req); expect(r.message.content).toBe("Hello"); }); it("should throw on error", async () => { mockChat.mockRejectedValue(new Error("fail")); await expect(service.chat(req)).rejects.toThrow(ServiceUnavailableException); }); });
+  describe("chatStream", () => { it("should yield chunks", async () => { mockChat.mockResolvedValue((async function* () { yield { model: "m", message: { role: "a", content: "x" }, done: true }; })()); const chunks = []; for await (const c of service.chatStream({ model: "m", messages: [{ role: "user", content: "x" }], stream: true })) chunks.push(c); expect(chunks.length).toBe(1); }); });
+  describe("embed", () => { it("should return embeddings", async () => { mockEmbed.mockResolvedValue({ model: "m", embeddings: [[0.1]] }); const r = await service.embed({ model: "m", input: ["x"] }); expect(r.embeddings).toEqual([[0.1]]); }); });
+});

apps/api/src/llm/llm.service.ts

@@ -0,0 +1,20 @@
+import { Injectable, OnModuleInit, Logger, ServiceUnavailableException } from "@nestjs/common";
+import { Ollama, Message } from "ollama";
+import type { ChatRequestDto, ChatResponseDto, EmbedRequestDto, EmbedResponseDto, ChatStreamChunkDto } from "./dto";
+export interface OllamaConfig { host: string; timeout?: number; }
+export interface OllamaHealthStatus { healthy: boolean; host: string; error?: string; models?: string[]; }
+@Injectable()
+export class LlmService implements OnModuleInit {
+  private readonly logger = new Logger(LlmService.name);
+  private client: Ollama;
+  private readonly config: OllamaConfig;
+  constructor() { this.config = { host: process.env["OLLAMA_HOST"] ?? "http://localhost:11434", timeout: parseInt(process.env["OLLAMA_TIMEOUT"] ?? "120000", 10) }; this.client = new Ollama({ host: this.config.host }); this.logger.log("Ollama service initialized"); }
+  async onModuleInit(): Promise<void> { const h = await this.checkHealth(); if (h.healthy) this.logger.log("Ollama healthy"); else this.logger.warn("Ollama unhealthy: " + (h.error ?? "unknown")); }
+  async checkHealth(): Promise<OllamaHealthStatus> { try { const r = await this.client.list(); return { healthy: true, host: this.config.host, models: r.models.map(m => m.name) }; } catch (e: unknown) { return { healthy: false, host: this.config.host, error: e instanceof Error ? e.message : String(e) }; } }
+  async listModels(): Promise<string[]> { try { return (await this.client.list()).models.map(m => m.name); } catch (e: unknown) { const msg = e instanceof Error ? e.message : String(e); this.logger.error("Failed to list models: " + msg); throw new ServiceUnavailableException("Failed to list models: " + msg); } }
+  async chat(request: ChatRequestDto): Promise<ChatResponseDto> { try { const msgs = this.buildMessages(request); const r = await this.client.chat({ model: request.model, messages: msgs, stream: false, options: { temperature: request.temperature, num_predict: request.maxTokens } }); return { model: r.model, message: { role: r.message.role as "assistant", content: r.message.content }, done: r.done, totalDuration: r.total_duration, promptEvalCount: r.prompt_eval_count, evalCount: r.eval_count }; } catch (e: unknown) { const msg = e instanceof Error ? e.message : String(e); this.logger.error("Chat failed: " + msg); throw new ServiceUnavailableException("Chat completion failed: " + msg); } }
+  async *chatStream(request: ChatRequestDto): AsyncGenerator<ChatStreamChunkDto> { try { const stream = await this.client.chat({ model: request.model, messages: this.buildMessages(request), stream: true, options: { temperature: request.temperature, num_predict: request.maxTokens } }); for await (const c of stream) yield { model: c.model, message: { role: c.message.role as "assistant", content: c.message.content }, done: c.done }; } catch (e: unknown) { const msg = e instanceof Error ? e.message : String(e); this.logger.error("Stream failed: " + msg); throw new ServiceUnavailableException("Streaming failed: " + msg); } }
+  async embed(request: EmbedRequestDto): Promise<EmbedResponseDto> { try { const r = await this.client.embed({ model: request.model, input: request.input, truncate: request.truncate === "none" ? false : true }); return { model: r.model, embeddings: r.embeddings, totalDuration: r.total_duration }; } catch (e: unknown) { const msg = e instanceof Error ? e.message : String(e); this.logger.error("Embed failed: " + msg); throw new ServiceUnavailableException("Embedding failed: " + msg); } }
+  private buildMessages(req: ChatRequestDto): Message[] { const msgs: Message[] = []; if (req.systemPrompt && !req.messages.some(m => m.role === "system")) msgs.push({ role: "system", content: req.systemPrompt }); for (const m of req.messages) msgs.push({ role: m.role, content: m.content }); return msgs; }
+  getConfig(): OllamaConfig { return { ...this.config }; }
+}

apps/web/src/components/gantt/GanttChart.test.tsx

@@ -91,7 +91,7 @@ describe("GanttChart", () => {
       render(<GanttChart tasks={tasks} />);
       
       const taskRow = screen.getAllByText("Completed Task")[0].closest("[role='row']");
-      expect(taskRow).toHaveClass(/completed/i);
+      expect(taskRow?.className).toMatch(/Completed/i);
     });
 
     it("should visually distinguish in-progress tasks", () => {
@@ -106,7 +106,7 @@ describe("GanttChart", () => {
       render(<GanttChart tasks={tasks} />);
       
       const taskRow = screen.getAllByText("Active Task")[0].closest("[role='row']");
-      expect(taskRow).toHaveClass(/in-progress/i);
+      expect(taskRow?.className).toMatch(/InProgress/i);
     });
   });
 
@@ -354,28 +354,36 @@ describe("GanttChart", () => {
     });
   });
 
-  describe("Dependencies (stretch goal)", () => {
+  describe("Dependencies", () => {
     it("should render dependency lines when showDependencies is true", () => {
       const tasks = [
         createGanttTask({
           id: "task-1",
           title: "Foundation",
+          startDate: new Date("2026-02-01"),
+          endDate: new Date("2026-02-10"),
         }),
         createGanttTask({
           id: "task-2",
           title: "Build on top",
+          startDate: new Date("2026-02-11"),
+          endDate: new Date("2026-02-20"),
           dependencies: ["task-1"],
         }),
       ];
       
       render(<GanttChart tasks={tasks} showDependencies={true} />);
       
-      // Check if dependency visualization exists
+      // Check if dependency SVG exists
       const chart = screen.getByRole("region", { name: /gantt chart/i });
       expect(chart).toBeInTheDocument();
       
-      // Specific dependency rendering will depend on implementation
+      // Look for dependency path element
-      // This is a basic check that the prop is accepted
+      const svg = chart.querySelector(".gantt-dependencies");
+      expect(svg).toBeInTheDocument();
+      
+      const paths = chart.querySelectorAll(".dependency-line");
+      expect(paths).toHaveLength(1);
     });
 
     it("should not render dependencies by default", () => {
@@ -396,6 +404,138 @@ describe("GanttChart", () => {
       // Dependencies should not be shown by default
       const chart = screen.getByRole("region", { name: /gantt chart/i });
       expect(chart).toBeInTheDocument();
+      
+      const svg = chart.querySelector(".gantt-dependencies");
+      expect(svg).not.toBeInTheDocument();
+    });
+
+    it("should handle tasks with non-existent dependencies gracefully", () => {
+      const tasks = [
+        createGanttTask({
+          id: "task-1",
+          title: "Task 1",
+          dependencies: ["non-existent-task"],
+        }),
+      ];
+      
+      render(<GanttChart tasks={tasks} showDependencies={true} />);
+      
+      // Should not crash
+      const chart = screen.getByRole("region", { name: /gantt chart/i });
+      expect(chart).toBeInTheDocument();
+    });
+
+    it("should render multiple dependency lines", () => {
+      const tasks = [
+        createGanttTask({
+          id: "task-1",
+          title: "Task 1",
+          startDate: new Date("2026-02-01"),
+          endDate: new Date("2026-02-05"),
+        }),
+        createGanttTask({
+          id: "task-2",
+          title: "Task 2",
+          startDate: new Date("2026-02-01"),
+          endDate: new Date("2026-02-05"),
+        }),
+        createGanttTask({
+          id: "task-3",
+          title: "Task 3",
+          startDate: new Date("2026-02-06"),
+          endDate: new Date("2026-02-10"),
+          dependencies: ["task-1", "task-2"],
+        }),
+      ];
+      
+      render(<GanttChart tasks={tasks} showDependencies={true} />);
+      
+      const chart = screen.getByRole("region", { name: /gantt chart/i });
+      const paths = chart.querySelectorAll(".dependency-line");
+      expect(paths).toHaveLength(2);
+    });
+  });
+
+  describe("Milestones", () => {
+    it("should render milestone as diamond shape", () => {
+      const milestone = createGanttTask({
+        id: "milestone-1",
+        title: "Phase 1 Complete",
+        startDate: new Date("2026-02-15"),
+        endDate: new Date("2026-02-15"),
+        isMilestone: true,
+      });
+      
+      render(<GanttChart tasks={[milestone]} />);
+      
+      const milestoneElement = screen.getByRole("button", {
+        name: /milestone.*phase 1 complete/i,
+      });
+      expect(milestoneElement).toBeInTheDocument();
+      expect(milestoneElement).toHaveClass("gantt-milestone");
+    });
+
+    it("should handle click on milestone", async () => {
+      const user = userEvent.setup();
+      const onTaskClick = vi.fn();
+      
+      const milestone = createGanttTask({
+        id: "milestone-1",
+        title: "Milestone Task",
+        isMilestone: true,
+      });
+      
+      render(<GanttChart tasks={[milestone]} onTaskClick={onTaskClick} />);
+      
+      const milestoneElement = screen.getByRole("button", {
+        name: /milestone.*milestone task/i,
+      });
+      await user.click(milestoneElement);
+      
+      expect(onTaskClick).toHaveBeenCalledWith(milestone);
+    });
+
+    it("should support keyboard navigation for milestones", async () => {
+      const user = userEvent.setup();
+      const onTaskClick = vi.fn();
+      
+      const milestone = createGanttTask({
+        id: "milestone-1",
+        title: "Keyboard Milestone",
+        isMilestone: true,
+      });
+      
+      render(<GanttChart tasks={[milestone]} onTaskClick={onTaskClick} />);
+      
+      const milestoneElement = screen.getByRole("button", {
+        name: /milestone/i,
+      });
+      
+      await user.tab();
+      expect(milestoneElement).toHaveFocus();
+      
+      await user.keyboard("{Enter}");
+      expect(onTaskClick).toHaveBeenCalled();
+    });
+
+    it("should render milestones and regular tasks together", () => {
+      const tasks = [
+        createGanttTask({
+          id: "task-1",
+          title: "Regular Task",
+          isMilestone: false,
+        }),
+        createGanttTask({
+          id: "milestone-1",
+          title: "Milestone",
+          isMilestone: true,
+        }),
+      ];
+      
+      render(<GanttChart tasks={tasks} />);
+      
+      expect(screen.getByRole("button", { name: /gantt bar.*regular task/i })).toBeInTheDocument();
+      expect(screen.getByRole("button", { name: /milestone.*milestone/i })).toBeInTheDocument();
     });
   });
 });

apps/web/src/components/gantt/GanttChart.tsx

@@ -3,7 +3,20 @@
 import type { GanttTask, GanttChartProps, TimelineRange, GanttBarPosition } from "./types";
 import { TaskStatus } from "@mosaic/shared";
 import { formatDate, isPastTarget, isApproachingTarget } from "@/lib/utils/date-format";
-import { useMemo } from "react";
+import { useMemo, useCallback } from "react";
+import styles from "./gantt.module.css";
+
+/**
+ * Represents a dependency line between two tasks
+ */
+interface DependencyLine {
+  fromTaskId: string;
+  toTaskId: string;
+  fromX: number;
+  fromY: number;
+  toX: number;
+  toY: number;
+}
 
 /**
  * Calculate the timeline range from a list of tasks
@@ -99,11 +112,11 @@ function getStatusClass(status: TaskStatus): string {
 function getRowStatusClass(status: TaskStatus): string {
   switch (status) {
     case TaskStatus.COMPLETED:
-      return "gantt-row-completed";
+      return styles.rowCompleted;
     case TaskStatus.IN_PROGRESS:
-      return "gantt-row-in-progress";
+      return styles.rowInProgress;
     case TaskStatus.PAUSED:
-      return "gantt-row-paused";
+      return styles.rowPaused;
     default:
       return "";
   }
@@ -135,6 +148,65 @@ function generateTimelineLabels(range: TimelineRange): Array<{ label: string; po
   return labels;
 }
 
+/**
+ * Calculate dependency lines between tasks
+ */
+function calculateDependencyLines(
+  tasks: GanttTask[],
+  timelineRange: TimelineRange
+): DependencyLine[] {
+  const lines: DependencyLine[] = [];
+  const taskIndexMap = new Map<string, number>();
+  
+  // Build index map
+  tasks.forEach((task, index) => {
+    taskIndexMap.set(task.id, index);
+  });
+  
+  const { start: rangeStart, totalDays } = timelineRange;
+  
+  tasks.forEach((task, toIndex) => {
+    if (!task.dependencies || task.dependencies.length === 0) {
+      return;
+    }
+    
+    task.dependencies.forEach((depId) => {
+      const fromIndex = taskIndexMap.get(depId);
+      if (fromIndex === undefined) {
+        return;
+      }
+      
+      const fromTask = tasks[fromIndex];
+      
+      // Calculate positions (as percentages)
+      const fromEndOffset = Math.max(
+        0,
+        (fromTask.endDate.getTime() - rangeStart.getTime()) / (1000 * 60 * 60 * 24)
+      );
+      const toStartOffset = Math.max(
+        0,
+        (task.startDate.getTime() - rangeStart.getTime()) / (1000 * 60 * 60 * 24)
+      );
+      
+      const fromX = (fromEndOffset / totalDays) * 100;
+      const toX = (toStartOffset / totalDays) * 100;
+      const fromY = fromIndex * 48 + 24; // Center of the row
+      const toY = toIndex * 48 + 24;
+      
+      lines.push({
+        fromTaskId: depId,
+        toTaskId: task.id,
+        fromX,
+        fromY,
+        toX,
+        toY,
+      });
+    });
+  });
+  
+  return lines;
+}
+
 /**
  * Main Gantt Chart Component
  */
@@ -155,20 +227,32 @@ export function GanttChart({
   // Generate timeline labels
   const timelineLabels = useMemo(() => generateTimelineLabels(timelineRange), [timelineRange]);
 
-  const handleTaskClick = (task: GanttTask) => (): void => {
+  // Calculate dependency lines
-    if (onTaskClick) {
+  const dependencyLines = useMemo(
-      onTaskClick(task);
+    () => (showDependencies ? calculateDependencyLines(sortedTasks, timelineRange) : []),
-    }
+    [showDependencies, sortedTasks, timelineRange]
-  };
+  );
 
-  const handleKeyDown = (task: GanttTask) => (e: React.KeyboardEvent<HTMLDivElement>): void => {
+  const handleTaskClick = useCallback(
-    if (e.key === "Enter" || e.key === " ") {
+    (task: GanttTask) => (): void => {
-      e.preventDefault();
       if (onTaskClick) {
         onTaskClick(task);
       }
-    }
+    },
-  };
+    [onTaskClick]
+  );
+
+  const handleKeyDown = useCallback(
+    (task: GanttTask) => (e: React.KeyboardEvent<HTMLDivElement>): void => {
+      if (e.key === "Enter" || e.key === " ") {
+        e.preventDefault();
+        if (onTaskClick) {
+          onTaskClick(task);
+        }
+      }
+    },
+    [onTaskClick]
+  );
 
   return (
     <div
@@ -242,11 +326,68 @@ export function GanttChart({
                 ))}
               </div>
 
-              {/* Task bars */}
+              {/* Dependency lines SVG */}
+              {showDependencies && dependencyLines.length > 0 && (
+                <svg
+                  className="gantt-dependencies absolute inset-0 pointer-events-none overflow-visible"
+                  style={{ width: "100%", height: `${sortedTasks.length * 48}px` }}
+                  aria-hidden="true"
+                >
+                  <defs>
+                    <marker
+                      id="arrowhead"
+                      markerWidth="10"
+                      markerHeight="7"
+                      refX="9"
+                      refY="3.5"
+                      orient="auto"
+                    >
+                      <polygon points="0 0, 10 3.5, 0 7" fill="#6b7280" />
+                    </marker>
+                  </defs>
+                  {dependencyLines.map((line) => (
+                    <path
+                      key={`dep-${line.fromTaskId}-${line.toTaskId}`}
+                      d={`M ${line.fromX}% ${line.fromY} C ${line.fromX + 2}% ${line.fromY}, ${line.toX - 2}% ${line.toY}, ${line.toX}% ${line.toY}`}
+                      stroke="#6b7280"
+                      strokeWidth="2"
+                      fill="none"
+                      markerEnd="url(#arrowhead)"
+                      className="dependency-line"
+                    />
+                  ))}
+                </svg>
+              )}
+
+              {/* Task bars and milestones */}
               {sortedTasks.map((task, index) => {
                 const position = calculateBarPosition(task, timelineRange, index);
                 const statusClass = getStatusClass(task.status);
                 
+                // Render milestone as diamond shape
+                if (task.isMilestone === true) {
+                  return (
+                    <div
+                      key={task.id}
+                      role="button"
+                      tabIndex={0}
+                      aria-label={`Milestone: ${task.title}, on ${formatDate(task.startDate)}`}
+                      className="gantt-milestone absolute cursor-pointer transition-all hover:opacity-80 focus:outline-none focus:ring-2 focus:ring-blue-500"
+                      style={{
+                        left: position.left,
+                        top: `${position.top + 8}px`,
+                      }}
+                      onClick={handleTaskClick(task)}
+                      onKeyDown={handleKeyDown(task)}
+                    >
+                      <div
+                        className={`w-6 h-6 transform rotate-45 ${statusClass}`}
+                        title={task.title}
+                      />
+                    </div>
+                  );
+                }
+                
                 return (
                   <div
                     key={task.id}
@@ -281,19 +422,6 @@ export function GanttChart({
           </div>
         </div>
       </div>
-
-      {/* CSS for status classes */}
-      <style jsx>{`
-        .gantt-row-completed {
-          background-color: #f0fdf4;
-        }
-        .gantt-row-in-progress {
-          background-color: #eff6ff;
-        }
-        .gantt-row-paused {
-          background-color: #fefce8;
-        }
-      `}</style>
     </div>
   );
 }

apps/web/src/components/gantt/gantt.module.css

@@ -0,0 +1,12 @@
+/* Gantt Chart Status Row Styles */
+.rowCompleted {
+  background-color: #f0fdf4; /* green-50 */
+}
+
+.rowInProgress {
+  background-color: #eff6ff; /* blue-50 */
+}
+
+.rowPaused {
+  background-color: #fefce8; /* yellow-50 */
+}

apps/web/src/components/gantt/index.test.ts

@@ -0,0 +1,23 @@
+import { describe, it, expect } from "vitest";
+import {
+  GanttChart,
+  toGanttTask,
+  toGanttTasks,
+} from "./index";
+
+describe("Gantt module exports", () => {
+  it("should export GanttChart component", () => {
+    expect(GanttChart).toBeDefined();
+    expect(typeof GanttChart).toBe("function");
+  });
+
+  it("should export toGanttTask helper", () => {
+    expect(toGanttTask).toBeDefined();
+    expect(typeof toGanttTask).toBe("function");
+  });
+
+  it("should export toGanttTasks helper", () => {
+    expect(toGanttTasks).toBeDefined();
+    expect(typeof toGanttTasks).toBe("function");
+  });
+});

apps/web/src/components/gantt/index.ts

@@ -1,7 +1,13 @@
 /**
  * Gantt Chart component exports
+ * @module gantt
  */
 
 export { GanttChart } from "./GanttChart";
-export type { GanttTask, GanttChartProps, TimelineRange, GanttBarPosition } from "./types";
+export type {
+  GanttTask,
+  GanttChartProps,
+  TimelineRange,
+  GanttBarPosition,
+} from "./types";
 export { toGanttTask, toGanttTasks } from "./types";

apps/web/src/components/gantt/types.test.ts

@@ -116,6 +116,50 @@ describe("Gantt Types Helpers", () => {
       expect(ganttTask?.dependencies).toBeUndefined();
     });
 
+    it("should extract isMilestone from metadata", () => {
+      const task = createTask({
+        metadata: {
+          startDate: "2026-02-01",
+          isMilestone: true,
+        },
+        dueDate: new Date("2026-02-15"),
+      });
+
+      const ganttTask = toGanttTask(task);
+
+      expect(ganttTask).not.toBeNull();
+      expect(ganttTask?.isMilestone).toBe(true);
+    });
+
+    it("should default isMilestone to false when not specified", () => {
+      const task = createTask({
+        metadata: {
+          startDate: "2026-02-01",
+        },
+        dueDate: new Date("2026-02-15"),
+      });
+
+      const ganttTask = toGanttTask(task);
+
+      expect(ganttTask).not.toBeNull();
+      expect(ganttTask?.isMilestone).toBe(false);
+    });
+
+    it("should handle non-boolean isMilestone in metadata", () => {
+      const task = createTask({
+        metadata: {
+          startDate: "2026-02-01",
+          isMilestone: "yes",
+        },
+        dueDate: new Date("2026-02-15"),
+      });
+
+      const ganttTask = toGanttTask(task);
+
+      expect(ganttTask).not.toBeNull();
+      expect(ganttTask?.isMilestone).toBe(false);
+    });
+
     it("should preserve all original task properties", () => {
       const task = createTask({
         id: "special-task",

apps/web/src/components/gantt/types.ts

@@ -16,6 +16,8 @@ export interface GanttTask extends Task {
   endDate: Date;
   /** Optional array of task IDs that this task depends on */
   dependencies?: string[];
+  /** Whether this task is a milestone (zero-duration marker) */
+  isMilestone?: boolean;
 }
 
 /**
@@ -56,31 +58,50 @@ export interface GanttChartProps {
   showDependencies?: boolean;
 }
 
+/**
+ * Type guard to check if a value is a valid date string
+ */
+function isDateString(value: unknown): value is string {
+  return typeof value === 'string' && !isNaN(Date.parse(value));
+}
+
+/**
+ * Type guard to check if a value is an array of strings
+ */
+function isStringArray(value: unknown): value is string[] {
+  return Array.isArray(value) && value.every((item) => typeof item === 'string');
+}
+
 /**
  * Helper to convert a base Task to GanttTask
  * Uses createdAt as startDate if not in metadata, dueDate as endDate
  */
 export function toGanttTask(task: Task): GanttTask | null {
   // For Gantt chart, we need both start and end dates
-  const startDate =
+  const metadataStartDate = task.metadata?.startDate;
-    (task.metadata?.startDate as string | undefined)
+  const startDate = isDateString(metadataStartDate)
-      ? new Date(task.metadata.startDate as string)
+    ? new Date(metadataStartDate)
-      : task.createdAt;
+    : task.createdAt;
-  
+
-  const endDate = task.dueDate || new Date();
+  const endDate = task.dueDate ?? new Date();
 
   // Validate dates
   if (!startDate || !endDate) {
     return null;
   }
 
+  // Extract dependencies with type guard
+  const metadataDependencies = task.metadata?.dependencies;
+  const dependencies = isStringArray(metadataDependencies)
+    ? metadataDependencies
+    : undefined;
+
   return {
     ...task,
     startDate,
     endDate,
-    dependencies: Array.isArray(task.metadata?.dependencies)
+    dependencies,
-      ? (task.metadata.dependencies as string[])
+    isMilestone: task.metadata?.isMilestone === true,
-      : undefined,
   };
 }
 

pnpm-lock.yaml

@@ -147,6 +147,15 @@ importers:
 
   apps/web:
     dependencies:
+      '@dnd-kit/core':
+        specifier: ^6.3.1
+        version: 6.3.1(react-dom@19.2.4(react@19.2.4))(react@19.2.4)
+      '@dnd-kit/sortable':
+        specifier: ^10.0.0
+        version: 10.0.0(@dnd-kit/core@6.3.1(react-dom@19.2.4(react@19.2.4))(react@19.2.4))(react@19.2.4)
+      '@dnd-kit/utilities':
+        specifier: ^3.2.2
+        version: 3.2.2(react@19.2.4)
       '@mosaic/shared':
         specifier: workspace:*
         version: link:../../packages/shared
@@ -586,6 +595,28 @@ packages:
     resolution: {integrity: sha512-Vd/9EVDiu6PPJt9yAh6roZP6El1xHrdvIVGjyBsHR0RYwNHgL7FJPyIIW4fANJNG6FtyZfvlRPpFI4ZM/lubvw==}
     engines: {node: '>=18'}
 
+  '@dnd-kit/accessibility@3.1.1':
+    resolution: {integrity: sha512-2P+YgaXF+gRsIihwwY1gCsQSYnu9Zyj2py8kY5fFvUM1qm2WA2u639R6YNVfU4GWr+ZM5mqEsfHZZLoRONbemw==}
+    peerDependencies:
+      react: '>=16.8.0'
+
+  '@dnd-kit/core@6.3.1':
+    resolution: {integrity: sha512-xkGBRQQab4RLwgXxoqETICr6S5JlogafbhNsidmrkVv2YRs5MLwpjoF2qpiGjQt8S9AoxtIV603s0GIUpY5eYQ==}
+    peerDependencies:
+      react: '>=16.8.0'
+      react-dom: '>=16.8.0'
+
+  '@dnd-kit/sortable@10.0.0':
+    resolution: {integrity: sha512-+xqhmIIzvAYMGfBYYnbKuNicfSsk4RksY2XdmJhT+HAC01nix6fHCztU68jooFiMUB01Ky3F0FyOvhG/BZrWkg==}
+    peerDependencies:
+      '@dnd-kit/core': ^6.3.0
+      react: '>=16.8.0'
+
+  '@dnd-kit/utilities@3.2.2':
+    resolution: {integrity: sha512-+MKAJEOfaBe5SmV6t34p80MMKhjvUz0vRrvVJbPT0WElzaOJ/1xs+D+KDv+tD/NE5ujfrChEcshd4fLn0wpiqg==}
+    peerDependencies:
+      react: '>=16.8.0'
+
   '@emnapi/runtime@1.8.1':
     resolution: {integrity: sha512-mehfKSMWjjNol8659Z8KxEMrdSJDDot5SXMq00dM8BN4o+CLNXQ0xH2V7EchNHV4RmbZLmmPdEaXZc5H2FXmDg==}
 
@@ -4760,6 +4791,31 @@ snapshots:
 
   '@csstools/css-tokenizer@3.0.4': {}
 
+  '@dnd-kit/accessibility@3.1.1(react@19.2.4)':
+    dependencies:
+      react: 19.2.4
+      tslib: 2.8.1
+
+  '@dnd-kit/core@6.3.1(react-dom@19.2.4(react@19.2.4))(react@19.2.4)':
+    dependencies:
+      '@dnd-kit/accessibility': 3.1.1(react@19.2.4)
+      '@dnd-kit/utilities': 3.2.2(react@19.2.4)
+      react: 19.2.4
+      react-dom: 19.2.4(react@19.2.4)
+      tslib: 2.8.1
+
+  '@dnd-kit/sortable@10.0.0(@dnd-kit/core@6.3.1(react-dom@19.2.4(react@19.2.4))(react@19.2.4))(react@19.2.4)':
+    dependencies:
+      '@dnd-kit/core': 6.3.1(react-dom@19.2.4(react@19.2.4))(react@19.2.4)
+      '@dnd-kit/utilities': 3.2.2(react@19.2.4)
+      react: 19.2.4
+      tslib: 2.8.1
+
+  '@dnd-kit/utilities@3.2.2(react@19.2.4)':
+    dependencies:
+      react: 19.2.4
+      tslib: 2.8.1
+
   '@emnapi/runtime@1.8.1':
     dependencies:
       tslib: 2.8.1