feat: read/write project config as agent-accessible tool

[zeroasterisk]

Problem

Agents cannot programmatically read or modify their project's configuration (templates, env vars, shared directories, agent defaults). This prevents agents from:

• Self-replicating project setups across environments
• Adjusting their own project config based on task requirements
• Exporting project config for backup or migration

Proposed Solution

Expose project configuration via the Hub API or as agent-accessible tools:

Read config

scion project config get --format json

Returns: templates list, env vars (names only, not values), shared directories, agent defaults, project metadata.

Write config

scion project config set --from-file config.json

Applies: template assignments, env var names (values provided separately via secrets), shared directory mappings.

Security Considerations

This could be a security concern and may warrant restricted implementation:

• Read config: Low risk if secrets/values are excluded (only names and structure). Medium risk if it exposes env var values or connection strings.
• Write config: Medium-high risk — an agent modifying its own project config could escalate privileges, change template assignments, or alter env vars that affect other agents in the same project.

Possible mitigations

• Read-only by default, write requires explicit admin approval
• Write operations logged and auditable
• Env var values never readable (only names)
• Secrets never included in read or write
• Write restricted to project-level settings, not hub-level
• Rate limiting on config writes

Use Cases

1. Agent sets up a new project to match a known-good configuration
2. Agent exports its project config for documentation or replication
3. CI/CD pipeline provisions projects programmatically
4. Agent adjusts template assignments based on task type