feat(linkedin-studio): N7.5 — MR-F9 etterspørsels-sveip (Tier-5-kilder + smertepunkt + vokabular-oversettelse + arc-kontrakt) [skip-docs]

The «innenfra og ut» demand-sweep: the mechanism that FILLS the N6 reader fields
(readerQuestion/painPoint/saturation). Discovery finds "what happened"; this layer
translates it into "the problem the reader is stuck on".

- demand-spotter agent (agents 19->20, inherits session): three passes after
  discovery, before drafting — demand-sweep -> pain-point map -> vocabulary translation.
- Tier 5 demand sources in config/trends-sources.template.md (inverse of Tier 1-4;
  honest blind spots: YouTube API, Reddit approximate, HN/GitHub ground truth).
- demand signal on TrendRecord (strength + answered) — rankable twin of the verbatim
  saturation text; additive-optional, store schema stays v4 (no migration).
- arc.ts (§4 output contract): groupIntoArcs (relatedIds transitive closure),
  rankArcQuestions (etterspørsel x kan-svare x ikke-besvart), classifyMarketGap
  (supply-gap != demand-gap != saturated). Pure + deterministic (TDD).
- arcs CLI verb + /linkedin:trends --demand mode (commands stay 30); morning brief
  shows the per-candidate demand signal.

Suites: trends 276->300, test-runner 139->140, tsc clean. Others unchanged
(brain 134, hooks 140, tests 35, render 60).

MR-F9 built (bygget-men-ubevist) — the (a)/(b)/(c) evidence gate is a runtime
demonstration, proven consumer-side (plugin agents don't resolve in the dev repo).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014bE7VbkmR3cqHFEeGfzgwb

CHANGELOG.md

@@ -5,6 +5,21 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+### Added — demand-sweep «innenfra og ut» (N7.5 / MR-F9)
+
+- **`demand-spotter` agent** — the demand-side twin of `trend-spotter`. Discovery finds *what happened*; the sweep translates it into *the reader's problem* via three passes after discovery, before drafting: demand-sweep (verbatim questions from where readers ask) → pain-point map → vocabulary translation (the reader's words, not the field's jargon). Inherits the session model; agents 19 → 20.
+- **Tier 5 demand sources** — a new tier in the source-list convention (`config/trends-sources.template.md`): practitioner forums, GitHub issues on spec repos, procurement data, regulator guidance, channel comments — the inverse of the Tier 1–4 supply sources. Known blind spots stated honestly (YouTube JS-rendered → API; Reddit approximate; HN/GitHub = ground truth; an honest null is a finding).
+- **`demand` signal on the trend record** — the rankable twin of the verbatim `saturation` text: `strength` (etterspørsel: strong/moderate/thin) + `answered` (is it already answered). Additive-optional; store schema stays v4 (no migration). Absent ⇒ unmeasured (the honest null the sweep may return instead of inventing demand).
+- **Arc (åre) output contract §4** — `scripts/trends/src/arc.ts`: groups demand-swept records into veins (relatedIds transitive closure), ranks each vein's questions on `etterspørsel × kan-svare × ikke-besvart`, and classifies an honest **market verdict** distinguishing a **supply-gap** (many ask, none answer — write here) from a **demand-gap** (few ask, but the sender can answer — high value, low audience) from **saturated** (skip). Pure + deterministic.
+- **`arcs` CLI verb + `/linkedin:trends --demand` mode** — render the §4 arc map (`node --import tsx src/cli.ts arcs`), reachable via the command's new demand mode (delegates to `demand-spotter`, keeps commands at 30). The morning brief also shows the per-candidate demand signal alongside the existing reader fields.
+- Trends suite 276 → 300; test-runner 139 → 140; `tsc --noEmit` clean.
+
+### Built feedback (awaiting consumer-side proof)
+
+- **MR-F9** (demand-sweep «innenfra og ut») — built; the (a)/(b)/(c) evidence gate is a runtime demonstration, proven consumer-side (plugin agents don't resolve in the dev repo).
+
 ## [0.7.0] - 2026-07-23
 
 **Trend engine → production bridge.** The discovery pass becomes a first-class command, gains a reader-side proposal + actionability layer, and is wired directly into the long-form pipeline: a trend now flows id-traceably from discovery to a scheduled edition, and a candidate with no formulable reader-grip can no longer inflate the top band.