fix(decisions): address PR #126 review — cross-refs, index, arithmetic

- Fix D-189 cross-ref: D-131 → content.md (was scope.md), fix anchor slug
- Fix D-191 cross-refs: D-093, D-095, D-138 → content.md (were architecture.md)
- Fix architecture.md footer counter: 52 → 53
- Fix D-190 ratio arithmetic: 1:100 → 1:80, 1:20-50 → 1:16-40
- Merge Destilaria Confluência/Lento into single row, update corp count ~28 → ~27
- Fix platform shorthand → platform_catalogue in D-189 §11
- Add D-189, D-190, D-191 to decisions/README.md index

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

decisions/economics.md

@@ -330,7 +330,7 @@ This domain covers: currency system, commodity taxonomy, shadow economy, corpora
   - Brands without volume tiers are economically marginal regardless of prestige — population asymmetry (10B systems vs. 50k) makes this structurally necessary
 
   **4. Brand Census**
-  - Notable (hand-authored): 120–170 corps with TOML records; ~28 currently named
+  - Notable (hand-authored): 120–170 corps with TOML records; ~27 currently named
   - Minor (template-generated): ~10,000 brands from ~120–130 template definitions (35–40 archetypes × 3 sub-variants), corridor-specific naming patterns, 3 scale tiers
   - Naming patterns: corridor-appropriate — north_reach = British/Australian inflection, east_reach = Korean/Japanese, west_reach = German/Dutch/Nordic, south_reach = Portuguese/Swahili, inner_corridor = pan-corridor neutral, frontier = founder surname + noun
   - Queryable content: `brand_products JOIN corp_presence` filtered by location and `product_subcategory`; sub-millisecond at 10K+ rows — primary use case alongside economic simulation
@@ -373,26 +373,25 @@ This domain covers: currency system, commodity taxonomy, shadow economy, corpora
   - Phase 2 (this sprint cycle): brand corps as commodity demand stubs in tâtonnement, `brand_products` / `brand_inputs` / `system_fiscal` schema, `corp_financial_state` passive tracking, `generate_brands` pipeline
   - Brand layer (post-Phase 2): pricing engine, awareness propagation, cultural preference curves, aging pipeline simulation, lifecycle state machine, player acquisition verbs
 
-  **11. Named Brand Corps (~28)**
+  **11. Named Brand Corps (~27)**
   | Corp | Category | Origin |
   |------|----------|--------|
   | Calloway Distillery | terroir | north_reach |
   | VGV | terroir | west_reach |
   | thrds | heritage_craft | north_reach |
   | Bífröst Marmor | terroir | north_reach / Compact |
-  | Destilaria Confluência | terroir | south_reach |
-  | Lento | terroir | south_reach |
+  | Destilaria Confluência / Lento | terroir | south_reach |
   | Veldfontein Botanical | terroir + heritage_craft | south_reach |
   | Comptoir Lendel | terroir + service_premium | inner_core |
   | Maison Cinq | design_heritage | inner_core / Gateway |
   | MVG (Manifattura Veicoli Gherardi) | design_heritage | west_reach Italian |
   | Higashiyama Vehicle Engineering | tech_premium + design_heritage | east_reach |
   | Rijdbaar Personal Mobility | design_heritage | west_reach / Compact |
-  | Byeolbit Entertainment | cultural + platform | east_reach |
+  | Byeolbit Entertainment | cultural + platform_catalogue | east_reach |
   | Leerfeld Records | cultural | west_reach / Compact |
   | Vuma Sound | cultural | south_reach |
   | Resonance Premium | platform_catalogue | inner_core |
-  | Dalbit Systems | tech_premium + platform | east_reach |
+  | Dalbit Systems | tech_premium + platform_catalogue | east_reach |
   | Arclamp | cultural + design_heritage | inner_core |
   | Kellervolk | cultural | Compact |
   | Hangang Studio | platform_catalogue | east_reach |
@@ -407,7 +406,7 @@ This domain covers: currency system, commodity taxonomy, shadow economy, corpora
 - **Rationale:** Administered pricing is the correct model because brands violate all three tâtonnement assumptions: heterogeneity (Calloway ≠ VGV ≠ generic spirits), supply inelasticity (terroir production cannot respond to price signals per D-177), and Veblen demand effects (prestige goods can have upward-sloping demand). The one-way interface (commodity prices → brand input costs; brand output prices do NOT feed back into tâtonnement) is architecturally clean and matches the D-178 layer model. The identity/exotic split in cultural premium is the minimal structural addition needed to produce all three observed pricing curves (Scarcity-Distance, Dual-Peak, Aspirational Gradient). Population asymmetry (~80B total Reach population, systems ranging from 10B to <50k) makes the halo/volume tier pattern structurally necessary — brands from tiny worlds are astronomically exclusive and need volume derivatives to be economically relevant.
 - **Raised by:** Full planning team workshop, Sprint 34 (#811).
 - **Dissent:** None.
-- **Cross-reference:** [D-185](#d-185-brands-are-not-commodities) (brands are not commodities), [D-184](#d-184-commodity-catalog-36-types) (commodity catalog), [D-177](#d-177-productivity-constraints-lore-derived) (productivity constraints), [D-175](#d-175-corporation-taxonomy-and-prerequisite) (corporation taxonomy), [D-178](#d-178-economic-model-architecture) (economic model architecture), [D-180](#d-180-event-input-port) (event input port), [D-181](#d-181-signal-vocabulary) (signal vocabulary), [D-173](#d-173-commodity-taxonomy) (commodity taxonomy), [D-171](#d-171-three-currency-system) (three-currency system), [D-131](scope.md#d-131-economic-verb-vocabulary) (economic verb vocabulary), [D-118](scope.md#d-118-small-business-owner-starting-state) (small business owner starting state)
+- **Cross-reference:** [D-185](#d-185-brands-are-not-commodities) (brands are not commodities), [D-184](#d-184-commodity-catalog-36-types) (commodity catalog), [D-177](#d-177-productivity-constraints-lore-derived) (productivity constraints), [D-175](#d-175-corporation-taxonomy-and-prerequisite) (corporation taxonomy), [D-178](#d-178-economic-model-architecture) (economic model architecture), [D-180](#d-180-event-input-port) (event input port), [D-181](#d-181-signal-vocabulary) (signal vocabulary), [D-173](#d-173-commodity-taxonomy) (commodity taxonomy), [D-171](#d-171-three-currency-system) (three-currency system), [D-131](content.md#d-131-broad-economic-verb-vocabulary--life-verbs-not-tycoon-specific) (economic verb vocabulary), [D-118](scope.md#d-118-small-business-owner-starting-state--tycoon-is-aspiration-not-starting-position) (small business owner starting state)
 
 ---
 
@@ -417,8 +416,8 @@ This domain covers: currency system, commodity taxonomy, shadow economy, corpora
   - **Scale reference table (~80B Reach):**
     - Single-system local phenomenon: 100M–500M (1–5% of a 10B system)
     - Corridor-known hit: 250M–1B (~0.5% of corridor addressable population)
-    - Reach-wide genuine hit: ~1B (1 in 100 Reach population)
-    - All-time Reach canonical: 2B–5B (1 in 20–50 Reach population)
+    - Reach-wide genuine hit: ~1B (1 in 80 Reach population)
+    - All-time Reach canonical: 2B–5B (1 in 16–40 Reach population)
   - **Earth rule of thumb:** multiply Earth-scale phenomenon volumes by 12–15× for comparable cultural penetration. A 100M-seller on Earth ≈ 1.2–1.5B in the Reach.
   - **40M benchmark:** 40M units/streams Reach-wide = 0.04% penetration — a cult hit or successful regional release, not a cultural touchstone. 40M within a single large system (10B population) = 0.4% — respectable but not legendary.
   - **Authoring rule:** wiki volume figures for media brands and any good with `brand_category = cultural` must include a `reference_population` annotation alongside the count. "40M" is incomplete; "40M (west_reach corridor, ~10B addressable)" is correct. This applies to corporation production ceilings, media distribution figures, and market penetration estimates in wiki pages and TOML files.