feat(fuel-prices): add retail gasoline and diesel prices panel (#2150)

* feat(fuel-prices): add retail fuel prices panel and seeder

- Add ListFuelPrices proto RPC with FuelPrice/FuelCountryPrice messages
- Create seed-fuel-prices.mjs seeder with 5 sources: Malaysia (data.gov.my),
  Spain (minetur.gob.es), Mexico (datos.gob.mx), US EIA, EU oil bulletin CSV
- Add list-fuel-prices.ts RPC handler reading from Redis seed cache
- Wire handler into EconomicService handler.ts
- Register fuelPrices in cache-keys.ts, bootstrap.js, health.js, gateway.ts
- Add FuelPricesPanel frontend component with gasoline/diesel/source columns
- Wire panel into panel-layout.ts, App.ts (prime + refresh scheduler)
- Add panel config, command entry with fuel/gas/diesel/petrol keywords
- Add fuelPrices refresh interval (6h) in base.ts
- Add i18n keys in en.json (panels.fuelPrices + components.fuelPrices)

Task: fuel-prices

* fix(fuel-prices): add BR/NZ/UK sources, fix EU non-euro currency, review fixes

- Add fetchBrazil() — ANP CSVs (GASOLINA + DIESEL), Promise.allSettled for
  independent partial results, BRL→USD via FX
- Add fetchNewZealand() — MBIE weekly-table.csv, Board price national avg, NZD→USD
- Add fetchUK_ModeA() — CMA retailer JSON feeds (Asda/BP/JET/MFG/Sainsbury's/
  Morrisons), E10+B7 pence→GBP, max-date observedAt across retailers
- Fix EU non-euro members (BG/CZ/DK/HU/PL/RO/SE) using local currency FX on
  EUR-denominated prices — all EU entries now use currency:'EUR'
- Fix fetchBrazil Promise.all → Promise.allSettled (partial CSV failure no
  longer discards both fuels)
- Fix UK observedAt: keep latest date across retailers (not last-processed)
- Fix WoW anomaly: omit wowPct instead of setting to 0
- Lift parseEUPrice out of inner loop to module scope
- Pre-compute parseBRDate per row to avoid double-conversion
- Update infoTooltip: describe methodology without exposing source URLs
- Add BRL, NZD, GBP to FX symbols list

* fix(fuel-prices): fix 4 live data bugs found in external review

EU CSV: replace hardcoded 2024 URLs (both returning 404) with dynamic
discovery — scrape EC energy page for current CSV link, fall back to
generated YYYY-MM patterns for last 4 months.

NZ: live MBIE header has no Region column (Week,Date,Fuel,Variable,Value,
Unit,Status) — remove regionIdx guard that was forcing return []. Values
are in NZD c/L not NZD/L — divide by 100 before storing.

UK: last_updated is DD/MM/YYYY HH:mm:ss not ISO — parse to YYYY-MM-DD
before lexicographic max-date comparison; previous code stored the
seed-run date instead of the latest retailer timestamp.

Panel: source column fell back to — for diesel-only countries because it
only read gas?.source. Use (gas ?? dsl)?.source so diesel-only rows
display their source correctly.

docs/api/EconomicService.openapi.yaml

@@ -391,6 +391,32 @@ paths:
                         application/json:
                             schema:
                                 $ref: '#/components/schemas/Error'
+    /api/economic/v1/list-fuel-prices:
+        get:
+            tags:
+                - EconomicService
+            summary: ListFuelPrices
+            description: ListFuelPrices retrieves retail gasoline and diesel prices across 30+ countries.
+            operationId: ListFuelPrices
+            responses:
+                "200":
+                    description: Successful response
+                    content:
+                        application/json:
+                            schema:
+                                $ref: '#/components/schemas/ListFuelPricesResponse'
+                "400":
+                    description: Validation error
+                    content:
+                        application/json:
+                            schema:
+                                $ref: '#/components/schemas/ValidationError'
+                default:
+                    description: Error response
+                    content:
+                        application/json:
+                            schema:
+                                $ref: '#/components/schemas/Error'
 components:
     schemas:
         Error:
@@ -1137,3 +1163,70 @@ components:
                     type: string
                     description: Human-readable source string.
             description: NationalDebtEntry holds debt data for a single country.
+        ListFuelPricesRequest:
+            type: object
+        ListFuelPricesResponse:
+            type: object
+            properties:
+                countries:
+                    type: array
+                    items:
+                        $ref: '#/components/schemas/FuelCountryPrice'
+                fetchedAt:
+                    type: string
+                cheapestGasoline:
+                    type: string
+                cheapestDiesel:
+                    type: string
+                mostExpensiveGasoline:
+                    type: string
+                mostExpensiveDiesel:
+                    type: string
+                wowAvailable:
+                    type: boolean
+                prevFetchedAt:
+                    type: string
+                sourceCount:
+                    type: integer
+                    format: int32
+                countryCount:
+                    type: integer
+                    format: int32
+        FuelCountryPrice:
+            type: object
+            properties:
+                code:
+                    type: string
+                name:
+                    type: string
+                currency:
+                    type: string
+                flag:
+                    type: string
+                gasoline:
+                    $ref: '#/components/schemas/FuelPrice'
+                diesel:
+                    $ref: '#/components/schemas/FuelPrice'
+                fxRate:
+                    type: number
+                    format: double
+        FuelPrice:
+            type: object
+            properties:
+                usdPrice:
+                    type: number
+                    format: double
+                localPrice:
+                    type: number
+                    format: double
+                grade:
+                    type: string
+                source:
+                    type: string
+                available:
+                    type: boolean
+                wowPct:
+                    type: number
+                    format: double
+                observedAt:
+                    type: string