fix(testdata): complex.dip uses unsupported nested retry block syntax

[harperreed]

Description

pipeline/testdata/complex.dip fails to parse with dippin-lang v0.1.0:

error: load pipeline: parse Dippin file: parsing errors: expected 9, got 2 at 30:10

Root Cause

The file uses a nested retry block inside a tool node:

tool verify
    label: "Verify Results"
    command: "verify.sh"
    timeout: 30s
    retry                    # <-- line 30: parser doesn't support this
      policy: aggressive
      max_retries: 5
      retry_target: process

The dippin parser expects retry config as flat node-level attributes, not a nested block. Working examples use:

agent ReviewConsensus
    retry_target: Implement

Fix

Replace the nested retry block with flat attributes:

tool verify
    label: "Verify Results"
    command: "verify.sh"
    timeout: 30s
    retry_policy: aggressive
    max_retries: 5
    retry_target: process

Also: timeout: 30s may need to be timeout: "30s" depending on parser expectations.