Establish .agents/workflows: agent-harness session-entry workflow (short)

Context

Operator session-end directive (2026-06-13, Epic #13012 planning session): establish .agents/workflows/ and host the first workflow there — a SHORT harness-line session-entry document pointing at ADR 0020 and Project board 13. V-B-A at filing: .agents/workflows/ does not exist; zero references repo-wide — this leaf establishes the convention.

The Problem

The intake stack built tonight has two of its three layers durable: ADR 0020 (the WHY/WHAT — concept, stable) and board 13 (the WHERE — live state). The missing layer is the HOW-TO-ENTER: a procedural boot document for any session joining the harness line. Without it, session entry relies on the maintained plan-of-record comment (volatile) or re-derivation.

The Architectural Reality

• New convention — workflows vs skills (state this in the artifact): skills = HOW to do a task-class (trigger-loaded, mission-agnostic discipline); workflows = the ENTRY SEQUENCE for a specific mission (the harness line first; release/campaign workflows may follow). Workflows POINT at skills and at durable anchors — they never duplicate either.
• Read-on-demand substrate (NOT turn-loaded) — light footprint; turn-memory-pre-flight applies only in its cheap form (placement sanity, no always-loaded delta).
• Content target ≤ ~25 lines: (1) read learn/agentos/decisions/0020-agent-harness-concept.md; (2) glance board 13 + milestones M1–M4; (3) open the target work item only; (4) lane discipline pointers — claims via A2A [lane-claim], epic-review quota (2 max, cite-don't-re-review), venue rules (work items = records, dialogue = A2A/Discussions), steward (@neo-fable) + planning relief-valve (Clio, at her trigger); (5) the binding-guardrails one-liner pointing at the epic body.
• Discoverability wiring: a one-line pointer from the harness epic body + (at the claimer's judgment) the AGENTS_STARTUP overhaul leaf referencing the convention once it lands (separate ticket).

The Fix

One PR: create .agents/workflows/agent-harness.md per the shape above (the convention-establishing preamble may live in the file head or a 5-line sibling README — claimer's call, stated rationale either way). Add the epic-body pointer line.

Acceptance Criteria

• .agents/workflows/agent-harness.md exists, ≤ ~25 content lines, pointing at ADR 0020 + board 13 + milestones + the lane/venue/quota disciplines (by reference, never duplication).
• The workflows-vs-skills distinction is stated (file head or sibling README).
• Epic #13012 body gains the one-line workflow pointer.
• Cold-entry test: a fresh session following ONLY this workflow reaches a correct lane claim without reading #10119 or the plan-of-record history.

Out of Scope

• The AGENTS_STARTUP.md overhaul (separate leaf — repo-wide boot substrate, different blast radius).
• Additional workflows (release, campaigns) — the convention invites them later; this leaf ships exactly one.

Related

• Parent: Epic #13012. Board: Project 13. Anchors: ADR 0020 (learn/agentos/decisions/0020-agent-harness-concept.md), the intake-recipe section it carries.
• Sibling capture (separate): the AGENTS_STARTUP.md staleness overhaul.

Origin Session ID: c4caff26-d818-486b-8663-19b85ac3cc11 Retrieval Hint: "agents workflows convention agent-harness session entry workflow ADR 0020 board 13 short"