feat: add integration helpers and comprehensive tests for conditional flow logic

- Introduced new helper functions for creating flows and retrieving step states with skip and
error info
- Added detailed integration tests covering conditional step execution, skipping, cascade
behavior, and optional dependencies
- Included tests for 'if', 'ifNot', 'whenUnmet', 'whenFailed' conditions, and cascade vs
non-cascade skips
- Created a new test file for retries exhausted scenarios (placeholder for future tests)

Author: jumski

pkgs/edge-worker/tests/integration/flow/_conditionalHelpers.ts

@@ -0,0 +1,65 @@
+import type { postgres } from '../../sql.ts';
+import { compileFlow } from '@pgflow/dsl';
+import type { AnyFlow } from '@pgflow/dsl';
+
+// ============= Test Helpers for Conditional Flow Integration Tests =============
+
+/**
+ * Compiles a Flow and executes SQL statements to create it in the database.
+ */
+export const createFlowInDb = async (sql: postgres.Sql, flow: AnyFlow) => {
+  const statements = compileFlow(flow);
+  for (const stmt of statements) {
+    await sql.unsafe(stmt);
+  }
+};
+
+/**
+ * Extended step state info including skip details
+ */
+export interface StepStateWithSkip {
+  step_slug: string;
+  status: string;
+  skip_reason: string | null;
+  skipped_at: string | null;
+}
+
+/**
+ * Get step states with skip information
+ */
+export const getStepStatesWithSkip = async (
+  sql: postgres.Sql,
+  runId: string
+): Promise<StepStateWithSkip[]> => {
+  return await sql<StepStateWithSkip[]>`
+    SELECT step_slug, status, skip_reason, skipped_at
+    FROM pgflow.step_states
+    WHERE run_id = ${runId}
+    ORDER BY step_slug;
+  `;
+};
+
+/**
+ * Extended task info including error details
+ */
+export interface TaskWithError {
+  step_slug: string;
+  status: string;
+  error_message: string | null;
+  attempts_count: number;
+}
+
+/**
+ * Get step tasks with error information
+ */
+export const getStepTasksWithError = async (
+  sql: postgres.Sql,
+  runId: string
+): Promise<TaskWithError[]> => {
+  return await sql<TaskWithError[]>`
+    SELECT step_slug, status, error_message, attempts_count
+    FROM pgflow.step_tasks
+    WHERE run_id = ${runId}
+    ORDER BY step_slug, task_index;
+  `;
+};