feat: optional JSON metadata on tasks, projects, and initiatives

[danielkov]

Entity metadata

Tasks, projects, and initiatives now support an optional free-form JSON metadata field. This lets you attach arbitrary structured information — environment config, tracking IDs, custom fields — to any entity without being limited to text-only tags.

CLI usage:

granary project my-proj tasks create "deploy service" \
  --metadata '{"env": "production", "region": "us-east-1"}'

granary tasks update proj-task-1 \
  --metadata '{"env": "staging", "retries": 3}'

Metadata works the same way on projects (project create/update --metadata) and initiatives (initiative create/update --metadata).

Output behavior:

Metadata is included in --output json / --json output but is intentionally excluded from prompt and text formats, keeping those outputs clean for human and LLM consumption.

Event template access:

Metadata is embedded as a nested JSON object in all event payloads (task.created, task.updated, task.next, project.created, etc.), so event templates can reference individual metadata fields:

{metadata.env}
{metadata.region}
{metadata.config.timeout}

This enables metadata-driven automation — for example, a task.next handler that routes work based on {metadata.env} or {metadata.worktree}.

✻ Clauded...