fix(wiki): add silence topics for GJ 421B (Pedra Seca) and GJ 904 (Claraboia)

Pedra Seca: sealed water allocation records from fourth-generation drought.
Claraboia: founding cooperative dissolution dispute details.
Both headers corrected (M→K, M→F).

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

wiki/star-systems/GJ-421B/index.md

@@ -1,5 +1,5 @@
 # Pedra Seca
-**GJ 421B** | M-type | deep_frontier
+**GJ 421B** | K-type | deep_frontier
 
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@@ -38,6 +38,16 @@ Governance by community council with water-rights management as the primary gove
 
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+## Silence Topic
+
+The water allocation crisis of the fourth generation. Approximately seventy years after founding, a prolonged dry period — three consecutive years of rainfall below even the community's conservative planning thresholds — forced the council to invoke the charter's emergency allocation protocols for the first time. The protocols functioned as designed. The community survived. What is not discussed outside the council is how the emergency was resolved at the family level: which households accepted reduced allocations, which households were prioritized, and whether the allocation decisions tracked the founding families' political standing or the charter's stated criteria of need. The emergency allocation records exist. They are sealed by council vote and have remained sealed through every subsequent generation's review.
+
+## Narrative Hook
+
+A community built around water management that survived its worst drought — and sealed the records of how the emergency allocations were actually decided.
+
+---
+
 ## Topology
 <!-- READ-ONLY — regenerated from star-map.json edges -->
 - **Hop Distance from Gateway:** 16

wiki/star-systems/GJ-904/index.md

@@ -1,5 +1,5 @@
 # Claraboia
-**GJ 904** | M-type | deep_frontier
+**GJ 904** | F-type | deep_frontier
 
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@@ -40,9 +40,13 @@ No institutional presence. Governance by the founding cooperative's successor ch
 
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+## Silence Topic
+
+The specific governance dispute that dissolved the south_reach cooperative the founders came from. The founding narrative describes the dispute in terms of principle — an irreconcilable difference about how cooperative assets should be managed — without naming the cooperative, the winning faction, or the specific decision that triggered the fracture. The community's charter includes a dissolution protocol that addresses exactly the kind of failure the founders experienced. The protocol's existence acknowledges the founding trauma; its specificity suggests the founders documented what went wrong with enough precision to prevent it happening again. The documentation is in the charter. What it describes about the prior cooperative is not discussed with outsiders.
+
 ## Narrative Hook
 
-A community of cooperative exiles at hop 16, farming a biologically complex world under a bright F7V star, whose agricultural knowledge is accumulated from 150 years of negotiation with an ecology that was there first.
+A community of cooperative exiles at hop 16, farming a biologically complex world under a bright F7V star, whose charter's dissolution protocol is their most honest monument to the governance failure that sent them here.
 
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