feat: add Crush AI assistant support

openspec/changes/add-crush-support/proposal.md

@@ -0,0 +1,13 @@
+## Why
+Add support for Crush AI assistant in OpenSpec to enable developers to use Crush's enhanced capabilities for spec-driven development workflows.
+
+## What Changes
+- Add Crush slash command configurator for proposal, apply, and archive operations
+- Add Crush-specific AGENTS.md configuration template 
+- Update tool registry to include Crush configurator
+- **BREAKING**: None - this is additive functionality
+
+## Impact
+- Affected specs: cli-init (new tool option)
+- Affected code: src/core/configurators/slash/crush.ts, registry.ts
+- New files: .crush/commands/openspec/ (proposal.md, apply.md, archive.md)

openspec/changes/add-crush-support/specs/cli-init/spec.md

@@ -0,0 +1,21 @@
+## ADDED Requirements
+### Requirement: Crush Tool Support
+The system SHALL provide Crush AI assistant as a supported tool option during OpenSpec initialization.
+
+#### Scenario: Initialize project with Crush support
+- **WHEN** user runs `openspec init --tool crush`
+- **THEN** Crush-specific slash commands are configured in `.crush/commands/openspec/`
+- **AND** Crush AGENTS.md includes OpenSpec workflow instructions
+- **AND** Crush is registered as available configurator
+
+#### Scenario: Crush proposal command generation
+- **WHEN** Crush slash commands are configured
+- **THEN** `.crush/commands/openspec/proposal.md` contains proposal workflow with guardrails
+- **AND** Includes Crush-specific frontmatter with OpenSpec category and tags
+- **AND** Follows established slash command template pattern
+
+#### Scenario: Crush apply and archive commands
+- **WHEN** Crush slash commands are configured
+- **THEN** `.crush/commands/openspec/apply.md` contains implementation workflow
+- **AND** `.crush/commands/openspec/archive.md` contains archiving workflow
+- **AND** Both commands include appropriate frontmatter and references

openspec/changes/add-crush-support/tasks.md

@@ -0,0 +1,7 @@
+## 1. Implementation
+- [x] 1.1 Create CrushSlashCommandConfigurator class in src/core/configurators/slash/crush.ts
+- [x] 1.2 Define file paths for Crush commands (.crush/commands/openspec/)
+- [x] 1.3 Create Crush-specific frontmatter for proposal, apply, archive commands
+- [x] 1.4 Register Crush configurator in slash/registry.ts
+- [x] 1.5 Add Crush to available tools in cli-init command
+- [x] 1.6 Test integration with openspec init --tool crush

src/core/config.ts

@@ -19,6 +19,7 @@ export interface AIToolOption {
 export const AI_TOOLS: AIToolOption[] = [
   { name: 'Auggie (Augment CLI)', value: 'auggie', available: true, successLabel: 'Auggie' },
   { name: 'Claude Code', value: 'claude', available: true, successLabel: 'Claude Code' },
+  { name: 'Crush', value: 'crush', available: true, successLabel: 'Crush' },
   { name: 'Cursor', value: 'cursor', available: true, successLabel: 'Cursor' },
   { name: 'Factory Droid', value: 'factory', available: true, successLabel: 'Factory Droid' },
   { name: 'OpenCode', value: 'opencode', available: true, successLabel: 'OpenCode' },

src/core/configurators/slash/crush.ts

@@ -0,0 +1,42 @@
+import { SlashCommandConfigurator } from './base.js';
+import { SlashCommandId } from '../../templates/index.js';
+
+const FILE_PATHS: Record<SlashCommandId, string> = {
+  proposal: '.crush/commands/openspec/proposal.md',
+  apply: '.crush/commands/openspec/apply.md',
+  archive: '.crush/commands/openspec/archive.md'
+};
+
+const FRONTMATTER: Record<SlashCommandId, string> = {
+  proposal: `---
+name: OpenSpec: Proposal
+description: Scaffold a new OpenSpec change and validate strictly.
+category: OpenSpec
+tags: [openspec, change]
+---`,
+  apply: `---
+name: OpenSpec: Apply
+description: Implement an approved OpenSpec change and keep tasks in sync.
+category: OpenSpec
+tags: [openspec, apply]
+---`,
+  archive: `---
+name: OpenSpec: Archive
+description: Archive a deployed OpenSpec change and update specs.
+category: OpenSpec
+tags: [openspec, archive]
+---`
+};
+
+export class CrushSlashCommandConfigurator extends SlashCommandConfigurator {
+  readonly toolId = 'crush';
+  readonly isAvailable = true;
+
+  protected getRelativePath(id: SlashCommandId): string {
+    return FILE_PATHS[id];
+  }
+
+  protected getFrontmatter(id: SlashCommandId): string {
+    return FRONTMATTER[id];
+  }
+}

src/core/configurators/slash/registry.ts

@@ -9,6 +9,7 @@ import { GitHubCopilotSlashCommandConfigurator } from './github-copilot.js';
 import { AmazonQSlashCommandConfigurator } from './amazon-q.js';
 import { FactorySlashCommandConfigurator } from './factory.js';
 import { AuggieSlashCommandConfigurator } from './auggie.js';
+import { CrushSlashCommandConfigurator } from './crush.js';
 
 export class SlashCommandRegistry {
   private static configurators: Map<string, SlashCommandConfigurator> = new Map();
@@ -24,6 +25,7 @@ export class SlashCommandRegistry {
     const amazonQ = new AmazonQSlashCommandConfigurator();
     const factory = new FactorySlashCommandConfigurator();
     const auggie = new AuggieSlashCommandConfigurator();
+    const crush = new CrushSlashCommandConfigurator();
 
     this.configurators.set(claude.toolId, claude);
     this.configurators.set(cursor.toolId, cursor);
@@ -35,6 +37,7 @@ export class SlashCommandRegistry {
     this.configurators.set(amazonQ.toolId, amazonQ);
     this.configurators.set(factory.toolId, factory);
     this.configurators.set(auggie.toolId, auggie);
+    this.configurators.set(crush.toolId, crush);
   }
 
   static register(configurator: SlashCommandConfigurator): void {

test/core/init.test.ts

@@ -737,6 +737,66 @@ describe('InitCommand', () => {
       );
       expect(auggieChoice.configured).toBe(true);
     });
+
+    it('should create Crush slash command files with templates', async () => {
+      queueSelections('crush', DONE);
+
+      await initCommand.execute(testDir);
+
+      const crushProposal = path.join(
+        testDir,
+        '.crush/commands/openspec/proposal.md'
+      );
+      const crushApply = path.join(
+        testDir,
+        '.crush/commands/openspec/apply.md'
+      );
+      const crushArchive = path.join(
+        testDir,
+        '.crush/commands/openspec/archive.md'
+      );
+
+      expect(await fileExists(crushProposal)).toBe(true);
+      expect(await fileExists(crushApply)).toBe(true);
+      expect(await fileExists(crushArchive)).toBe(true);
+
+      const proposalContent = await fs.readFile(crushProposal, 'utf-8');
+      expect(proposalContent).toContain('---');
+      expect(proposalContent).toContain('name: OpenSpec: Proposal');
+      expect(proposalContent).toContain('description: Scaffold a new OpenSpec change and validate strictly.');
+      expect(proposalContent).toContain('category: OpenSpec');
+      expect(proposalContent).toContain('tags: [openspec, change]');
+      expect(proposalContent).toContain('<!-- OPENSPEC:START -->');
+      expect(proposalContent).toContain('**Guardrails**');
+
+      const applyContent = await fs.readFile(crushApply, 'utf-8');
+      expect(applyContent).toContain('---');
+      expect(applyContent).toContain('name: OpenSpec: Apply');
+      expect(applyContent).toContain('description: Implement an approved OpenSpec change and keep tasks in sync.');
+      expect(applyContent).toContain('category: OpenSpec');
+      expect(applyContent).toContain('tags: [openspec, apply]');
+      expect(applyContent).toContain('Work through tasks sequentially');
+
+      const archiveContent = await fs.readFile(crushArchive, 'utf-8');
+      expect(archiveContent).toContain('---');
+      expect(archiveContent).toContain('name: OpenSpec: Archive');
+      expect(archiveContent).toContain('description: Archive a deployed OpenSpec change and update specs.');
+      expect(archiveContent).toContain('category: OpenSpec');
+      expect(archiveContent).toContain('tags: [openspec, archive]');
+      expect(archiveContent).toContain('openspec archive <id> --yes');
+    });
+
+    it('should mark Crush as already configured during extend mode', async () => {
+      queueSelections('crush', DONE, 'crush', DONE);
+      await initCommand.execute(testDir);
+      await initCommand.execute(testDir);
+
+      const secondRunArgs = mockPrompt.mock.calls[1][0];
+      const crushChoice = secondRunArgs.choices.find(
+        (choice: any) => choice.value === 'crush'
+      );
+      expect(crushChoice.configured).toBe(true);
+    });
   });
 
   describe('non-interactive mode', () => {

test/core/update.test.ts

@@ -574,6 +574,84 @@ Old body
     await expect(FileSystemUtils.fileExists(auggieArchive)).resolves.toBe(false);
   });
 
+  it('should refresh existing Crush slash command files', async () => {
+    const crushPath = path.join(
+      testDir,
+      '.crush/commands/openspec/proposal.md'
+    );
+    await fs.mkdir(path.dirname(crushPath), { recursive: true });
+    const initialContent = `---
+name: OpenSpec: Proposal
+description: Old description
+category: OpenSpec
+tags: [openspec, change]
+---
+<!-- OPENSPEC:START -->
+Old slash content
+<!-- OPENSPEC:END -->`;
+    await fs.writeFile(crushPath, initialContent);
+
+    const consoleSpy = vi.spyOn(console, 'log');
+
+    await updateCommand.execute(testDir);
+
+    const updated = await fs.readFile(crushPath, 'utf-8');
+    expect(updated).toContain('name: OpenSpec: Proposal');
+    expect(updated).toContain('**Guardrails**');
+    expect(updated).toContain(
+      'Validate with `openspec validate <id> --strict`'
+    );
+    expect(updated).not.toContain('Old slash content');
+
+    const [logMessage] = consoleSpy.mock.calls[0];
+    expect(logMessage).toContain(
+      'Updated OpenSpec instructions (openspec/AGENTS.md'
+    );
+    expect(logMessage).toContain('AGENTS.md (created)');
+    expect(logMessage).toContain(
+      'Updated slash commands: .crush/commands/openspec/proposal.md'
+    );
+
+    consoleSpy.mockRestore();
+  });
+
+  it('should not create missing Crush slash command files on update', async () => {
+    const crushApply = path.join(
+      testDir,
+      '.crush/commands/openspec-apply.md'
+    );
+
+    // Only create apply; leave proposal and archive missing
+    await fs.mkdir(path.dirname(crushApply), { recursive: true });
+    await fs.writeFile(
+      crushApply,
+      `---
+name: OpenSpec: Apply
+description: Old description
+category: OpenSpec
+tags: [openspec, apply]
+---
+<!-- OPENSPEC:START -->
+Old body
+<!-- OPENSPEC:END -->`
+    );
+
+    await updateCommand.execute(testDir);
+
+    const crushProposal = path.join(
+      testDir,
+      '.crush/commands/openspec-proposal.md'
+    );
+    const crushArchive = path.join(
+      testDir,
+      '.crush/commands/openspec-archive.md'
+    );
+
+    // Confirm they weren't created by update
+    await expect(FileSystemUtils.fileExists(crushProposal)).resolves.toBe(false);
+    await expect(FileSystemUtils.fileExists(crushArchive)).resolves.toBe(false);
+  });
+
   it('should preserve Windsurf content outside markers during update', async () => {
     const wsPath = path.join(
       testDir,