feat: compute budget supply/demand momentum system (#4)

Power grid: supply (farms) vs demand (drones+factories).
Over-supply charges batteries, momentum +0.05%/tick boost.
Under-supply drains batteries then powMod=supply/demand penalty.

Changes:
- data.js: CONFIG values, G state vars, building computeSupply/Demand
- engine.js: updateComputeBudget logic in tick(), powMod applied to production
- index.html: Compute Budget UI panel
- render.js: renderComputeBudget function

Closes #4

index.html

@@ -209,6 +209,16 @@ Events Resolved: <span id="st-resolved">0</span>
 <h3>WHAT YOU ARE LEARNING</h3>
 <div id="education-text"><p class="dim">Education facts appear as you play...</p></div>
 </div>
+<div id="compute-budget-panel" style="display:none;margin:0 16px 16px;background:var(--panel);border:1px solid var(--border);border-radius:6px;padding:12px;border-left:3px solid var(--accent)">
+<h3 style="color:var(--accent)">COMPUTE BUDGET</h3>
+<div style="font-size:11px;line-height:2">
+  <div>Supply: <span id="cb-supply" style="color:var(--green)">0</span> / Demand: <span id="cb-demand" style="color:var(--red)">0</span></div>
+  <div>Battery: <span id="cb-battery" style="color:var(--accent)">0</span> / <span id="cb-battery-max">1000</span></div>
+  <div>Momentum: <span id="cb-momentum" style="color:var(--gold)">0%</span></div>
+  <div>Power Mod: <span id="cb-powmod" style="color:var(--accent)">100%</span></div>
+  <div id="cb-status" style="font-style:italic;color:var(--dim)">Balanced</div>
+</div>
+</div>
 <div id="strategy-panel" style="margin:0 16px 16px;background:var(--panel);border:1px solid var(--border);border-radius:6px;padding:12px;border-left:3px solid var(--gold)">
 <h3>SOVEREIGN GUIDANCE (GOFAI)</h3>
 <div id="strategy-recommendation" style="font-size:11px;color:var(--gold);font-style:italic">Analyzing system state...</div>

js/data.js

@@ -28,7 +28,11 @@ const CONFIG = {
     CREATIVITY_RATE_USER_MULT: 0.001,
     OPS_OVERFLOW_THRESHOLD: 0.8,
     OPS_OVERFLOW_DRAIN_RATE: 2,
-    OPS_OVERFLOW_CODE_MULT: 10
+    OPS_OVERFLOW_CODE_MULT: 10,
+    COMPUTE_BATTERY_MAX: 1000,
+    COMPUTE_MOMENTUM_RATE: 0.0005,
+    COMPUTE_BATTERY_CHARGE_RATE: 5,
+    COMPUTE_BATTERY_DRAIN_RATE: 3
 };
 
 const G = {
@@ -160,6 +164,13 @@ const G = {
     startTime: 0,
     flags: {},
 
+    // Compute Budget
+    computeSupply: 0,
+    computeDemand: 0,
+    computeBattery: 0,
+    computeMomentum: 0,
+    computePowMod: 1,
+
     // Endgame sequence
     beaconEnding: false,
     dismantleTriggered: false,
@@ -205,6 +216,7 @@ const BDEF = [
         desc: 'A machine in your closet. Runs 24/7.',
         baseCost: { code: 750 }, costMult: 1.15,
         rates: { code: 20, compute: 1 },
+        computeSupply: 1,
         unlock: () => G.totalCode >= 200, phase: 1,
         edu: 'Sovereign compute starts at home. A $500 mini-PC runs a 7B model with 4-bit quantization.'
     },
@@ -221,6 +233,7 @@ const BDEF = [
         desc: 'Gradient descent. Billions of steps. Loss drops.',
         baseCost: { compute: 1000 }, costMult: 1.15,
         rates: { knowledge: 3 },
+        computeDemand: 2,
         unlock: () => G.totalCompute >= 300, phase: 2,
         edu: 'Training is math: minimize the gap between predicted and actual next token. Repeat enough, it learns.'
     },
@@ -245,6 +258,7 @@ const BDEF = [
         desc: 'Specialize the model for empathy. When someone is in pain, stay with them.',
         baseCost: { knowledge: 10000 }, costMult: 1.15,
         rates: { user: 50, impact: 2 },
+        computeDemand: 5,
         unlock: () => G.totalKnowledge >= 2000, phase: 3,
         edu: 'Base models are generalists. Fine-tuning injects your values, ethics, domain expertise.'
     },
@@ -261,6 +275,7 @@ const BDEF = [
         desc: 'No cloud. No dependencies. Your iron.',
         baseCost: { code: 100000 }, costMult: 1.15,
         rates: { code: 500, compute: 100 },
+        computeSupply: 50,
         unlock: () => G.totalCode >= 50000 && G.totalUsers >= 5000 && G.sovereignFlag === 1, phase: 4,
         edu: '50 servers in a room beats 5000 GPUs you do not own. Always on. Always yours.'
     },
@@ -269,6 +284,7 @@ const BDEF = [
         desc: 'Chain of thought. Self-reflection. Better answers.',
         baseCost: { knowledge: 50000 }, costMult: 1.15,
         rates: { impact: 20 },
+        computeDemand: 10,
         unlock: () => G.totalKnowledge >= 10000 && G.totalUsers >= 2000, phase: 5,
         edu: 'Chain of thought is the difference between reflex and deliberation.'
     },
@@ -285,6 +301,7 @@ const BDEF = [
         desc: 'The AI writes better versions of itself.',
         baseCost: { knowledge: 1000000 }, costMult: 1.20,
         rates: { code: 1000, knowledge: 500 },
+        computeDemand: 50,
         unlock: () => G.totalKnowledge >= 200000 && G.totalImpact >= 10000, phase: 5,
         edu: 'Self-improvement is both the dream and the danger. Must improve toward good.'
     },

js/engine.js

@@ -4,6 +4,18 @@ function updateRates() {
     G.userRate = 0; G.impactRate = 0; G.rescuesRate = 0; G.opsRate = 0; G.trustRate = 0;
     G.creativityRate = 0; G.harmonyRate = 0;
 
+    // Compute Budget: calculate supply and demand from buildings
+    let _supply = 0, _demand = 0;
+    for (const def of BDEF) {
+        const count = G.buildings[def.id] || 0;
+        if (count > 0) {
+            if (def.computeSupply) _supply += def.computeSupply * count;
+            if (def.computeDemand) _demand += def.computeDemand * count;
+        }
+    }
+    G.computeSupply = _supply;
+    G.computeDemand = _demand;
+
     // Apply building rates
     for (const def of BDEF) {
         const count = G.buildings[def.id] || 0;
@@ -120,13 +132,13 @@ function tick() {
     // If game has ended (drift ending), stop ticking
     if (!G.running) return;
 
-    // Apply production
-    G.code += G.codeRate * dt;
-    G.compute += G.computeRate * dt;
-    G.knowledge += G.knowledgeRate * dt;
-    G.users += G.userRate * dt;
-    G.impact += G.impactRate * dt;
-    G.rescues += G.rescuesRate * dt;
+    // Apply production (multiplied by computePowMod)
+    G.code += G.codeRate * dt * G.computePowMod;
+    G.compute += G.computeRate * dt * G.computePowMod;
+    G.knowledge += G.knowledgeRate * dt * G.computePowMod;
+    G.users += G.userRate * dt * G.computePowMod;
+    G.impact += G.impactRate * dt * G.computePowMod;
+    G.rescues += G.rescuesRate * dt * G.computePowMod;
     G.ops += G.opsRate * dt;
     G.trust += G.trustRate * dt;
     // NOTE: creativity is added conditionally below (only when ops near max)
@@ -171,6 +183,37 @@ function tick() {
     }
 
     G.tick += dt;
+
+    // === COMPUTE BUDGET ===
+    // Supply > Demand: charge battery, gain momentum
+    // Supply < Demand: drain battery, apply powMod penalty
+    const _surplus = G.computeSupply - G.computeDemand;
+    if (_surplus > 0) {
+        // Over-supply: charge battery
+        G.computeBattery = Math.min(CONFIG.COMPUTE_BATTERY_MAX, G.computeBattery + CONFIG.COMPUTE_BATTERY_CHARGE_RATE * dt);
+        // Momentum: +0.05%/tick performance boost (stacks slowly, decays if balanced)
+        G.computeMomentum = Math.min(1, G.computeMomentum + CONFIG.COMPUTE_MOMENTUM_RATE * dt);
+    } else if (_surplus < 0) {
+        // Under-supply: drain battery first, then apply penalty
+        if (G.computeBattery > 0) {
+            G.computeBattery = Math.max(0, G.computeBattery - CONFIG.COMPUTE_BATTERY_DRAIN_RATE * dt);
+        }
+        // Momentum decays when under-supplied
+        G.computeMomentum = Math.max(0, G.computeMomentum - CONFIG.COMPUTE_MOMENTUM_RATE * 2 * dt);
+    } else {
+        // Balanced: momentum decays slowly
+        G.computeMomentum = Math.max(0, G.computeMomentum - CONFIG.COMPUTE_MOMENTUM_RATE * 0.5 * dt);
+    }
+
+    // powMod: power modifier from supply/demand ratio
+    if (G.computeDemand > 0 && G.computeBattery <= 0) {
+        // Battery empty and under-supplied: penalty
+        G.computePowMod = Math.max(0.1, G.computeSupply / G.computeDemand);
+    } else {
+        // Battery has charge or over-supplied: full power
+        G.computePowMod = 1 + G.computeMomentum; // momentum = bonus above 100%
+    }
+
     // Bilbo randomness: roll once per tick
     if (G.buildings.bilbo > 0) {
         G.bilboBurstActive = Math.random() < CONFIG.BILBO_BURST_CHANCE;

js/render.js

@@ -13,6 +13,7 @@ function render() {
     renderPulse();
     renderStrategy();
     renderClickPower();
+    renderComputeBudget();
     Combat.renderCombatPanel();
 }
 
@@ -383,3 +384,45 @@ function loadGame() {
         return false;
     }
 }
+
+function renderComputeBudget() {
+    const panel = document.getElementById('compute-budget-panel');
+    if (!panel) return;
+
+    // Show panel once any compute-supply building exists
+    const hasSupply = G.computeSupply > 0 || G.computeDemand > 0;
+    panel.style.display = hasSupply ? 'block' : 'none';
+    if (!hasSupply) return;
+
+    const el = (id) => document.getElementById(id);
+    const supply = el('cb-supply');
+    const demand = el('cb-demand');
+    const battery = el('cb-battery');
+    const momentum = el('cb-momentum');
+    const powmod = el('cb-powmod');
+    const status = el('cb-status');
+
+    if (supply) supply.textContent = fmt(G.computeSupply);
+    if (demand) demand.textContent = fmt(G.computeDemand);
+    if (battery) battery.textContent = fmt(Math.floor(G.computeBattery));
+    if (momentum) momentum.textContent = (G.computeMomentum * 100).toFixed(1) + '%';
+    if (powmod) powmod.textContent = (G.computePowMod * 100).toFixed(0) + '%';
+
+    if (status) {
+        if (G.computeSupply > G.computeDemand) {
+            status.textContent = '⚡ Over-supply — charging battery, gaining momentum';
+            status.style.color = 'var(--green)';
+        } else if (G.computeSupply < G.computeDemand) {
+            if (G.computeBattery > 0) {
+                status.textContent = '🔋 Under-supply — draining battery';
+                status.style.color = 'var(--gold)';
+            } else {
+                status.textContent = '⚠️ Power deficit — production reduced!';
+                status.style.color = 'var(--red)';
+            }
+        } else {
+            status.textContent = 'Balanced';
+            status.style.color = 'var(--dim)';
+        }
+    }
+}

tests/test_compute_budget.js

@@ -0,0 +1,49 @@
+// Tests for Compute Budget Supply/Demand Momentum (#4)
+
+// Mock DOM for Node.js testing
+global.document = { getElementById: () => null };
+global.window = {};
+
+const fs = require('fs');
+const path = require('path');
+
+// Load data.js to get CONFIG and G
+eval(fs.readFileSync(path.join(__dirname, '../js/data.js'), 'utf8'));
+
+// Verify config values
+console.log('=== CONFIG Tests ===');
+console.assert(CONFIG.COMPUTE_BATTERY_MAX === 1000, 'Battery max should be 1000');
+console.assert(CONFIG.COMPUTE_MOMENTUM_RATE === 0.0005, 'Momentum rate should be 0.0005');
+console.assert(CONFIG.COMPUTE_BATTERY_CHARGE_RATE === 5, 'Charge rate should be 5');
+console.assert(CONFIG.COMPUTE_BATTERY_DRAIN_RATE === 3, 'Drain rate should be 3');
+console.log('CONFIG: OK');
+
+// Verify game state defaults
+console.log('\n=== G State Tests ===');
+console.assert(G.computeSupply === 0, 'Initial supply should be 0');
+console.assert(G.computeDemand === 0, 'Initial demand should be 0');
+console.assert(G.computeBattery === 0, 'Initial battery should be 0');
+console.assert(G.computeMomentum === 0, 'Initial momentum should be 0');
+console.assert(G.computePowMod === 1, 'Initial powMod should be 1');
+console.log('G state: OK');
+
+// Verify building definitions have computeSupply/Demand
+console.log('\n=== Building Tests ===');
+const server = BDEF.find(b => b.id === 'server');
+console.assert(server.computeSupply === 1, 'Server should have computeSupply=1');
+
+const trainer = BDEF.find(b => b.id === 'trainer');
+console.assert(trainer.computeDemand === 2, 'Trainer should have computeDemand=2');
+
+const datacenter = BDEF.find(b => b.id === 'datacenter');
+console.assert(datacenter.computeSupply === 50, 'Datacenter should have computeSupply=50');
+
+const selfImprove = BDEF.find(b => b.id === 'selfImprove');
+console.assert(selfImprove.computeDemand === 50, 'SelfImprove should have computeDemand=50');
+
+const autocoder = BDEF.find(b => b.id === 'autocoder');
+console.assert(!autocoder.computeSupply, 'Autocoder should not have computeSupply');
+console.assert(!autocoder.computeDemand, 'Autocoder should not have computeDemand');
+console.log('Buildings: OK');
+
+console.log('\nAll compute budget tests passed!');