fix(energy): V6 review findings (7 issues across 5 PRs) (#2861)

* fix(energy): V6 review findings — flow availability, ember proto bool, LNG stale/blocking, fixture accuracy

- Fix 1: Only show "Flow data unavailable" for chokepoints with PortWatch
  flow coverage (hormuz, malacca, suez, bab_el_mandeb), not all corridors
- Fix 2: Correct proto comment on data_available field 9 to document
  gas mode and both mode behavior
- Fix 3: Add ember_available bool field 50 to GetCountryEnergyProfile proto,
  set server-side from spine.electricity or direct Ember key fallback
- Fix 4: Ember fallback reads energy:ember:v1:{code} when spine exists but
  has no electricity block (or fossilShare is absent)
- Fix 6: Add IEA upstream fixture matching actual API response shape,
  with golden test parsing through seeder parseRecord/buildIndex
- Fix 7: Add PortWatch ArcGIS fixture with all attributes.* fields used
  by buildHistory, with golden test validating parsed output

* fix(energy): add emberAvailable to energy gate; use real buildHistory in portwatch test

* fix(energy): add Ember render block to renderEnergyProfile for Ember-only countries

* chore: regenerate OpenAPI specs after proto comment update

docs/api/IntelligenceService.openapi.yaml

@@ -2207,6 +2207,29 @@ components:
                     type: boolean
                 ieaBelowObligation:
                     type: boolean
+                emberFossilShare:
+                    type: number
+                    format: double
+                    description: Phase 3 — Ember monthly electricity mix
+                emberRenewShare:
+                    type: number
+                    format: double
+                emberNuclearShare:
+                    type: number
+                    format: double
+                emberCoalShare:
+                    type: number
+                    format: double
+                emberGasShare:
+                    type: number
+                    format: double
+                emberDemandTwh:
+                    type: number
+                    format: double
+                emberDataMonth:
+                    type: string
+                emberAvailable:
+                    type: boolean
         ComputeEnergyShockScenarioRequest:
             type: object
             properties: