feat: Phase 3 — wire panel modules (heatmap, agent-board, dual-brain, LoRA, sovereignty, earth)

- core/theme.js: export NEXUS with full NEXUS.theme.* properties used by all 6 panels
- core/ticker.js: add subscribe() convenience export so panels can self-register
- data/gitea.js: also write state.agentStatus, activeAgentCount, zoneIntensity, commits, commitHashes
- data/loaders.js: also write state.sovereignty
- data/bitcoin.js: also write state.blockHeight, lastBlockHeight, newBlockDetected, starPulseIntensity
- data/weather.js: also write state.weather
- app.js: import + init all 6 panel modules, bootstrap data polling, call globalTicker.tick()

Fixes #412
Refs #409

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

modules/data/bitcoin.js

@@ -1,6 +1,8 @@
 // modules/data/bitcoin.js — Blockstream block height polling
-// Writes to S: lastKnownBlockHeight, _starPulseIntensity
+// Writes to S: lastKnownBlockHeight, _starPulseIntensity (legacy)
+// Writes to state: blockHeight, lastBlockHeight, newBlockDetected, starPulseIntensity
 import { S } from '../state.js';
+import { state } from '../core/state.js';
 
 const BITCOIN_REFRESH_MS = 60 * 1000;
 
@@ -11,12 +13,15 @@ export async function fetchBlockHeight() {
     const height = parseInt(await res.text(), 10);
     if (isNaN(height)) return null;
 
-    const isNew = S.lastKnownBlockHeight !== null && height > S.lastKnownBlockHeight;
+    const prev = S.lastKnownBlockHeight;
+    const isNew = prev !== null && height > prev;
     S.lastKnownBlockHeight = height;
+    if (isNew) S._starPulseIntensity = 1.0;
 
-    if (isNew) {
-      S._starPulseIntensity = 1.0;
-    }
+    state.blockHeight = height;
+    state.lastBlockHeight = prev || 0;
+    state.newBlockDetected = isNew;
+    if (isNew) state.starPulseIntensity = 1.0;
 
     return { height, isNewBlock: isNew };
   } catch {