feat(scenarios): sign-post disruptive measures in the creation journey

Internal wall and floor insulation (and room-in-roof) involve major
internal works, and landlords often exclude them. Encode that domain
knowledge once as DISRUPTIVE_MEASURES in the scenario model (with
plain-language reasons; guarded by a key-validity test) and surface it
three ways:

- measures step: allowed disruptive chips carry an amber "disruptive"
  tag + amber border, with the reason in the tooltip; a legend explains
  the marking
- "Low disruption" quick-start now excludes exactly this set, so the
  preset and the badges cannot drift apart
- review step: an amber nudge lists any disruptive measures still
  allowed before saving

New CONTEXT.md term: Disruptive measure.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

CONTEXT.md

@@ -88,6 +88,10 @@ _Avoid_: target (reserve for the EPC band specifically), objective
 An optional per-Scenario spending cap, denominated **per property (£)** — never a whole-portfolio envelope. Absent budget = no cap.
 _Avoid_: portfolio budget (a separate concept on the Portfolio row), envelope, cost limit
 
+**Disruptive measure**:
+A measure whose installation involves major internal works for residents (internal wall insulation, solid/suspended floor insulation, room-in-roof insulation). Landlords frequently exclude them; the UI sign-posts them and the "Low disruption" quick-start excludes exactly this set. Canonical list: `DISRUPTIVE_MEASURES` in the Scenario domain model.
+_Avoid_: invasive (unused here), wet trades (a narrower, overlapping set: plaster-and-screed work)
+
 **Measure exclusion**:
 A Scenario constraint that takes a measure off the table for the optimiser. The *only* measure-constraint concept on a Scenario — there is no stored inclusion list; "only Solar PV + ASHP" is expressed by excluding everything else. An empty exclusion set is valid and means every measure is available.
 _Avoid_: inclusions, allowed measures (as a stored concept — UI may present "allowed/excluded" toggles, but what's captured is the exclusion set)

src/app/portfolio/[slug]/(portfolio)/scenarios/new/NewScenarioJourney.tsx

@@ -10,7 +10,7 @@ import {
   measuresList,
   type MeasureKey,
 } from "@/app/db/schema/recommendations";
-import { EPC_BANDS, findExactDuplicate, SCENARIO_GOALS } from "@/lib/scenarios/model";
+import { DISRUPTIVE_MEASURES, EPC_BANDS, findExactDuplicate, SCENARIO_GOALS } from "@/lib/scenarios/model";
 import { BandChip, EPC_SOFT, GOAL_DESCRIPTIONS, GOAL_SHORT_LABELS, GoalIcon, bandInk, bandTint, formatMoney } from "../ui";
 
 interface ExistingScenario {
@@ -36,8 +36,8 @@ const PRESETS: { label: string; hint: string; excl: MeasureKey[] }[] = [
     excl: ["internal_wall_insulation", "external_wall_insulation", "solid_floor_insulation"] },
   { label: "Fabric only", hint: "Insulation and glazing only — no heating systems or renewables",
     excl: ["boiler_upgrade", "high_heat_retention_storage_heaters", "air_source_heat_pump", "secondary_heating", "hot_water_tank_insulation", "cylinder_thermostat", "solar_pv", "low_energy_lighting", "fireplace", "ventilation"] },
-  { label: "Low disruption", hint: "Nothing that requires residents to move out or clear rooms",
-    excl: ["internal_wall_insulation", "external_wall_insulation", "solid_floor_insulation", "suspended_floor_insulation", "room_roof_insulation"] },
+  { label: "Low disruption", hint: "Excludes every measure marked as disruptive",
+    excl: Object.keys(DISRUPTIVE_MEASURES) as MeasureKey[] },
 ];
 
 const fieldLabel =
@@ -356,11 +356,19 @@ export function NewScenarioJourney({
               <h3 className="font-manrope text-lg font-extrabold text-brandblue">
                 Which measures are on the table?
               </h3>
-              <p className="mb-6 mt-1 max-w-[60ch] text-sm text-gray-600">
+              <p className="mb-2 mt-1 max-w-[60ch] text-sm text-gray-600">
                 Everything is allowed unless you rule it out. Click a measure to
                 exclude it — the engine chooses the best mix from whatever
                 remains.
               </p>
+              <p className="mb-5 max-w-[60ch] text-[13px] text-gray-400">
+                Measures marked{" "}
+                <span className="font-manrope text-[9px] font-extrabold uppercase tracking-[.08em] text-amber-600">
+                  disruptive
+                </span>{" "}
+                involve major internal works — landlords often exclude them.
+                Hover one to see why.
+              </p>
               <div className="mb-3 flex flex-wrap items-center gap-2">
                 <span className="mr-1 font-manrope text-[11px] font-extrabold uppercase tracking-[.1em] text-gray-400">
                   Quick starts
@@ -397,14 +405,22 @@ export function NewScenarioJourney({
                   <div className="flex flex-wrap gap-2">
                     {keys.map((k) => {
                       const off = excluded.has(k);
+                      const disruptiveReason = DISRUPTIVE_MEASURES[k];
                       return (
                         <button
                           key={k}
                           aria-pressed={off}
+                          title={
+                            disruptiveReason
+                              ? `Disruptive: ${disruptiveReason}. Landlords often exclude this.`
+                              : undefined
+                          }
                           className={`inline-flex items-center gap-2 rounded-full border px-3.5 py-1.5 text-[13px] transition ${
                             off
                               ? "border-gray-200 bg-gray-100 text-gray-400 line-through hover:border-gray-300"
-                              : "border-gray-200 bg-white text-brandblue hover:border-gray-400"
+                              : disruptiveReason
+                                ? "border-amber-200 bg-white text-brandblue hover:border-amber-400"
+                                : "border-gray-200 bg-white text-brandblue hover:border-gray-400"
                           }`}
                           onClick={() =>
                             setExcluded((prev) => {
@@ -419,6 +435,11 @@ export function NewScenarioJourney({
                             {off ? "✕" : "✓"}
                           </span>
                           {measuresDisplayLabels[k]}
+                          {disruptiveReason && !off && (
+                            <span className="font-manrope text-[9px] font-extrabold uppercase tracking-[.08em] text-amber-600">
+                              disruptive
+                            </span>
+                          )}
                         </button>
                       );
                     })}
@@ -438,6 +459,24 @@ export function NewScenarioJourney({
                 Check the configuration — it can&apos;t be changed once saved (you
                 can rename later). A different question is a new scenario.
               </p>
+              {(() => {
+                const allowedDisruptive = (
+                  Object.keys(DISRUPTIVE_MEASURES) as MeasureKey[]
+                ).filter((k) => !excluded.has(k));
+                return allowedDisruptive.length > 0 ? (
+                  <div className="mb-5 max-w-[62ch] rounded-xl border border-amber-200 bg-amber-50 px-4 py-3 text-[13px] text-amber-900">
+                    This scenario still allows{" "}
+                    <b>
+                      {allowedDisruptive
+                        .map((k) => measuresDisplayLabels[k])
+                        .join(", ")}
+                    </b>{" "}
+                    — disruptive measure{allowedDisruptive.length > 1 ? "s" : ""}{" "}
+                    landlords often exclude. Go back a step if you&apos;d rather
+                    rule {allowedDisruptive.length > 1 ? "them" : "it"} out.
+                  </div>
+                ) : null;
+              })()}
               {duplicateView && (
                 <div
                   role="alert"

src/lib/scenarios/model.test.ts

@@ -3,6 +3,7 @@ import { measuresList } from "@/app/db/schema/recommendations";
 import {
   constraintSummary,
   deriveScenarioStatus,
+  DISRUPTIVE_MEASURES,
   findExactDuplicate,
   parseExclusions,
   scenarioToInsertRow,
@@ -227,6 +228,14 @@ describe("findExactDuplicate", () => {
   });
 });
 
+describe("DISRUPTIVE_MEASURES", () => {
+  it("only marks real measure keys (a typo would silently drop the badge)", () => {
+    for (const key of Object.keys(DISRUPTIVE_MEASURES)) {
+      expect(measuresList).toContain(key);
+    }
+  });
+});
+
 describe("display helpers", () => {
   it("derives status from plan existence — no stored status column", () => {
     expect(deriveScenarioStatus(0)).toBe("awaiting_modelling");

src/lib/scenarios/model.ts

@@ -131,6 +131,21 @@ export function parseExclusions(text: string | null): string[] {
   return inner.split(",").map((s) => s.trim()).filter(Boolean);
 }
 
+/**
+ * Measures whose installation involves major internal works — landlords
+ * frequently exclude them. The value is the plain-language reason shown to
+ * users. The "Low disruption" quick-start excludes exactly this set.
+ */
+export const DISRUPTIVE_MEASURES: Partial<Record<MeasureKey, string>> = {
+  internal_wall_insulation:
+    "Rooms need clearing and replastering while the work is done",
+  solid_floor_insulation:
+    "Floors are dug up or raised — usually needs the home empty",
+  suspended_floor_insulation:
+    "Floorboards come up in every affected room",
+  room_roof_insulation: "Loft rooms are stripped back to the rafters",
+};
+
 export type ScenarioStatus = "modelled" | "awaiting_modelling";
 
 /** Status is derived from plan existence (ADR-0003) — never stored. */