feat: integrate workflow customization system

[Gaubee]

Summary

Integrate the customization system into built-in workflows, enabling configuration without full replacement.

Changes

New: workflow-config.schema.ts

Zod schemas for all workflow configurations:

Schema	Description
BaseWorkflowConfigSchema	Shared: tools, permissionMode, prompts
CoderConfigSchema	+ openspec (enabled, autoArchive)
ResearchConfigSchema	+ output (format, saveHtml, maxSources), search
GitCommitterConfigSchema	+ commit (style, maxTitleLength), push
MemoryConfigSchema	+ defaultLimit, defaultUserRelated

Updated Workflows

coder.workflow.ts:

• Uses prompt-loader for system prompt (user > builtin priority)
• Uses tools-merger for tool configuration
• Reads config from PreferencesContext

research.workflow.ts:

• Same integrations as coder

git-committer.workflow.ts:

• Uses tools-merger for tool configuration
• Reads config from PreferencesContext

New Helper

// common/async-context.ts
export function getContextWorkflowConfig<T>(workflowName: string): T | undefined

Usage Example

// user/preferences.ts
export default definePreferences((ctx, p) =>
  p
    .workflow("coder", (w) => w
      .config({
        tools: { allow: ["CustomTool"], disallow: ["!Task"] },
        permissionMode: "bypassPermissions",
        prompts: { customInstructions: "Always use TypeScript strict mode" },
      })
    )
    .build()
);

Tests

98 tests passing