[Look-Ahead §5] Update scenario-forecast.md (long-horizon-mode) and forward-indicators.md (multi-horizon decay)

[pethers]

Parent

Epic: #1562 · Foundation: PR #1561

Goal (Plan §5 template updates)

Two existing templates need updates so they cooperate cleanly with the new long-horizon artifacts shipped in PR #1561.

A. analysis/templates/scenario-forecast.md — long-horizon mode

• Add an optional long-horizon-mode header (frontmatter or first-section flag) that, when set, requires:
  • ≥6 scenarios (current floor is 4)
  • Mandatory branch on EP-election outcome (centre-right / centre-left / fragmented coalition)
  • Per-scenario WEP confidence band drawn from the decay table (see §9.3)
• When unset, today's behaviour is preserved (backward-compatible).
• Activated automatically when the workflow's registry entry has electoralOverlay === true OR scenarioMaxHorizonMonths >= 36.

B. analysis/templates/forward-indicators.md — multi-horizon decay table

• Add a multi-horizon decay table showing how each indicator's predictive value decays at 7d / 30d / 90d / 12m / term-end / EP-election horizons.
• Tag each indicator with the horizon(s) it belongs to (e.g. "rapporteur-deadline indicator" tagged 7d/30d only; "Spitzenkandidaten declared candidates" tagged 12m+).
• Cross-link to forward-projection-methodology.md for the canonical decay numbers.

Files to study

Concern	Files
Templates (targets)	analysis/templates/scenario-forecast.md, analysis/templates/forward-indicators.md
Methodology providing the contract	analysis/methodologies/forward-projection-methodology.md, analysis/methodologies/strategic-extensions-methodology.md
Registry that signals activation	src/config/article-horizons.ts (electoralOverlay, scenarioMaxHorizonMonths)
Validator floors	analysis/methodologies/reference-quality-thresholds.json (need ≥6-scenario gate when long-horizon-mode active)
Quality gate prompt	.github/prompts/03-analysis-completeness-gate.md, .github/prompts/11-forward-projection.md

Acceptance criteria

• scenario-forecast.md gains documented long-horizon-mode: true frontmatter flag with backward-compatible default
• Floors for ≥6 scenarios when flag is on are enforced (either via threshold JSON or validator code)
• forward-indicators.md gains the multi-horizon decay table + per-indicator horizon tags
• 11-forward-projection.md Stage-B prompt cross-links the new sections
• No double-source-of-truth — both templates point at forward-projection-methodology.md for the canonical decay numbers
• Re-validate one historical month-ahead run and one new election-cycle dry-run (synthetic fixture) — both should still pass / RED appropriately

Suggested agent

news-journalist (template + methodology authoring territory).

Do not assign Copilot yet.