chore(array): remove workflows and workflow stages

[joshsny]

we want to get rid of these as a concept, and just have task runs and agent types

[greptile-apps]

_{14 files reviewed, 1 comment}

_{Edit Code Review Agent Settings | Greptile}

[greptile-apps]

logic: filtering by runs__stage will match ANY run with that stage, not just the latest run

this changes the behavior from the previous code which used a subquery to filter by the stage of the latest run only

potential issues:

1. tasks with old runs in a stage will still appear even if their latest run is in a different stage
2. duplicate tasks if multiple runs have the same stage value (needs .distinct())

suggested fix:

Suggested change

	stage = params.get("stage")
	if stage:
	qs = qs.filter(runs__stage=stage)
	stage = params.get("stage")
	if stage:
	from django.db.models import OuterRef, Subquery
	latest_run = TaskRun.objects.filter(task=OuterRef("pk")).order_by("-created_at").values("stage")[:1]
	qs = qs.annotate(latest_stage=Subquery(latest_run)).filter(latest_stage=stage)

Prompt To Fix With AI

This is a comment left during a code review.
Path: products/tasks/backend/api.py
Line: 69:71

Comment:
**logic:** filtering by `runs__stage` will match ANY run with that stage, not just the latest run

this changes the behavior from the previous code which used a subquery to filter by the stage of the **latest run only**

potential issues:
1. tasks with old runs in a stage will still appear even if their latest run is in a different stage
2. duplicate tasks if multiple runs have the same stage value (needs `.distinct()`)

suggested fix:

```suggestion
        stage = params.get("stage")
        if stage:
            from django.db.models import OuterRef, Subquery
            latest_run = TaskRun.objects.filter(task=OuterRef("pk")).order_by("-created_at").values("stage")[:1]
            qs = qs.annotate(latest_stage=Subquery(latest_run)).filter(latest_stage=stage)
```

How can I resolve this? If you propose a fix, please make it concise.

[github-actions]

Migration SQL Changes

Hey 👋, we've detected some migrations on this PR. Here's the SQL output for each migration, make sure they make sense:

products/tasks/backend/migrations/0011_taskrun_stage_alter_task_current_stage_and_more.py

BEGIN;
--
-- Add field stage to taskrun
--
ALTER TABLE "posthog_task_run" ADD COLUMN "stage" varchar(100) NULL;
--
-- Alter field current_stage on task
--
-- (no-op)
--
-- Alter field workflow on task
--
-- (no-op)
--
-- Alter field current_stage on taskrun
--
-- (no-op)
COMMIT;

[github-actions]

🔍 Migration Risk Analysis

We've analyzed your migrations for potential risks.

Summary: 0 Safe | 1 Needs Review | 0 Blocked

⚠️ Needs Review

May have performance impact

tasks.0011_taskrun_stage_alter_task_current_stage_and_more
  └─ #1 ✅ AddField
     Adding nullable field is safe
     model: taskrun, field: stage
  └─ #2 ⚠️ AlterField
     Field alteration may cause table locks or data loss (check if changing type or constraints)
     model: task, field: current_stage, field_type: ForeignKey
  └─ #3 ⚠️ AlterField
     Field alteration may cause table locks or data loss (check if changing type or constraints)
     model: task, field: workflow, field_type: ForeignKey
  └─ #4 ⚠️ AlterField
     Field alteration may cause table locks or data loss (check if changing type or constraints)
     model: taskrun, field: current_stage, field_type: ForeignKey