Slice 1: flows-from-config foundation — resolveFlows + /pi-flow:run runs the first stage

[maikeffi]

Parent

#1

What to build

Replace the hardcoded pipeline engine with user-defined flows read from settings.json. A pure resolveFlows(userFlows) turns the top-level pi-flow.flows key in settings.json into a validated flow map: each flow has a description? and an ordered stages[]; each stage resolves to { skill, model?, mode } with defaults applied — missing mode → HITL, missing model → no model switch. Invalid shapes (a flow with no stages, a stage with no skill, a mode outside HITL/AFK) are rejected with a clear message.

Add /pi-flow:run <name> [input]. Its argument autocompletes resolved flow names (name + description as autocomplete items). Running a flow creates FlowState { flowId, stageIndex: 0, phase: "running", input, startedAt }, persists it, switches to the first stage's model if one is set, sends a generic kickoff message naming the skill (stage 1's kickoff carries the input), and renders the progress widget. Starting while a flow is active is refused with a "cancel first" notice; an unknown flow name errors.

This slice removes pipelines.ts, the /pi-flow:new-feature|improve-arch|debug commands, and the obsolete /pi-flow:setup (which configured the old design/code model pair). No stage advancement yet — that is the next slice.

Agreed contract:

interface FlowStage { skill: string; model?: string; mode?: "HITL" | "AFK" }
interface FlowDefinition { description?: string; stages: FlowStage[] }
// resolveFlows(userFlows) -> Record<string, FlowDefinition>, mode defaulted to "HITL"

Acceptance criteria

• resolveFlows applies defaults (missing mode → HITL, missing model → no switch) and returns a flow map keyed by name
• resolveFlows rejects a flow with zero stages, a stage missing skill, or an invalid mode
• /pi-flow:run <name> "input" sets state to running at stage 0 with the given input and persists it
• Running switches to the first stage's model only when the stage specifies one
• Running sends a kickoff message that names the stage's skill and includes the input
• The run argument autocompletes with resolved flow names and descriptions
• An unknown flow name notifies an error; starting while a flow is active notifies "cancel first"
• pipelines.ts and the new-feature/improve-arch/debug/setup commands are removed
• Behavior is covered through the existing pure-function and fake-ExtensionAPI seams

Blocked by

None - can start immediately