Spec

Input: [feature, selected option, or brief path] [--handoff | --prd]

Plan the input; if empty, the latest selected option, interview summary, or feature the user described. No feature or testable goal: name what is missing and stop. Several independent features: one plan each.

Return, in this order:

• Problem and requested outcome, with its source.
• In-scope behavior and exclusions that matter. No padding to a count.
• Shape of the change, limited to what must be agreed before coding: new or changed types and signatures, and the call tree or file tree with new nodes marked [new]. For an existing structure, show a diff of it.
• Acceptance criteria as a table: id (AC-1, AC-2, ...), actor, input or boundary, observable result, verification method. The method is a command or an observation a person can make without reading the code; a criterion without one keeps an empty method and also goes under Decisions needed.
• Assumptions with evidence; open questions separately.
• Failure scenarios that apply (malformed input, dependency failure, retries, races, partial writes), as a table: scenario, detection, response.
• Decisions needed, with owner when known and the evidence that would settle each.

Evidence rules:

• Verify that every cited path and symbol exists.
• External API behavior: cite docs or source for the version in use or proposed. An installed dependency proves nothing about its defaults or guarantees.
• Mark proposed files and tests [new].
• Never invent executed checks, expected log text, metrics, or user requirements.