draft: spindle: `org.tangled.*` endpoints #4562

phase 1: refactor spindle #

• deprecate events table. replace with dedicated pipelines and workflow_statuses tables.
• clean up pipelineId situation. pipelineId is just a record-key typed string. No embedded knot hostname. Workflow identifier is pipelineId + workflow name.

phase 2: port org.tangled.* xrpc methods #

wip

phase 3: (not in this PR) split event generation vs pipeline runner #

then we can extend "spindle" for multiple use cases like site deploy trigger or webhooks.