Implement missing ambient.json fields: startupPrompt and results

[jwm4]

Summary

The ambient.json workflow configuration schema includes fields that are documented but not implemented in the platform:

• startupPrompt - Workflow greeting message (documented as required)
• results - Artifact location patterns (documented as optional)

Reference: AMBIENT_JSON_SCHEMA.md

Current State

What the platform actually implements:

Field	Documented	Platform Implementation
name	Required	✅ Read (logging/metadata only)
description	Required	✅ Read (backend metadata)
systemPrompt	Required	✅ Used (injected into Claude's context)
startupPrompt	Required	❌ Not implemented
results	Optional	❌ Not implemented

The workaround

Workflow authors work around this by including instructions in systemPrompt that tell the agent to read .ambient/ambient.json using the Read tool. This makes the fields "accessible" but:

• Wastes tokens (platform already loaded the file)
• Fragile (depends on agent following instructions)
• No UI integration (frontend can't use results for artifact discovery)
• Indirect (platform has the data but doesn't use it)

Proposed Implementation

1. startupPrompt support

In components/runners/claude-code-runner/adapter.py:

ambient_config = self._load_ambient_config(cwd_path)

# Send workflow greeting as first message (if not a continuation)
if ambient_config.get('startupPrompt') and not is_continuation:
    # Send as initial assistant message or first prompt
    pass

2. results support

Options:

• Frontend artifact discovery: Expose patterns to UI for showing generated files
• Session completion summary: Use patterns to list outputs in status
• Inject into system prompt: So agent knows where to write without re-reading config

3. Update Go backend struct

In components/backend/handlers/content.go:

type AmbientConfig struct {
    Name         string            `json:"name"`
    Description  string            `json:"description"`
    SystemPrompt string            `json:"systemPrompt"`
    ArtifactsDir string            `json:"artifactsDir"`
    StartupPrompt string           `json:"startupPrompt"`  // NEW
    Results      map[string]string `json:"results"`        // NEW
}

Relevant Code Locations

• Python loader: components/runners/claude-code-runner/adapter.py:1691 (_load_ambient_config)
• Go struct: components/backend/handlers/content.go:716 (AmbientConfig)
• Design doc: docs/design/session-initialization-flow.md (mentions startupPrompt in pseudocode)

Acceptance Criteria

• startupPrompt sent as greeting when workflow activates (not on continuation)
• results patterns available to frontend for artifact discovery
• Update docs/reference/index.md to document actual implementation
• Add schema validation or at least warning for missing required fields