Harness planner

Selection procedure for the Planner persona. The prompt at agent/harness/planner-prompt.md is the contract; this is the method.

1. Establish state

Run bash agent/init.sh. It resolves the dependency closure and tells you what is genuinely unblocked, so you do not recompute it.

Read agent/harness/horizon.json. The previous run left a lookahead. Treat its head as the default choice and only depart from it with a reason you write down.

2. Build the candidate set

A candidate must satisfy all of:

• status is not completed
• every id in depends_on is completed
• it is not in the in-flight exclusion list appended to the prompt
• it advances at least one facet or outcome in agent/vision.md