Accessibility: ARIA labels on all buttons, fix exportSave race (#49)

index.html: ARIA roles, labels, live regions on all panels and static buttons
game.js: aria-label on dynamically generated building/project buttons
game.js: Fixed exportSave URL.revokeObjectURL race (delayed 1s)

game.js

@@ -1934,7 +1934,7 @@ function renderBuildings() {
 
         const rateStr = def.rates ? Object.entries(def.rates).map(([r, v]) => `+${v}/${r}/s`).join(', ') : '';
 
-        html += `<button class="build-btn ${afford ? 'can-buy' : ''}" onclick="buyBuilding('${def.id}')" title="${def.edu}">`;
+        html += `<button class="build-btn ${afford ? 'can-buy' : ''}" onclick="buyBuilding('${def.id}')" title="${def.edu}" aria-label="Buy ${def.name}, cost ${costStr}">`;
         html += `<span class="b-name">${def.name}</span>`;
         if (count > 0) html += `<span class="b-count">x${count}</span>`;
         html += `<span class="b-cost">Cost: ${costStr}</span>`;
@@ -1977,7 +1977,7 @@ function renderProjects() {
             const afford = canAffordProject(pDef);
             const costStr = Object.entries(pDef.cost).map(([r, a]) => `${fmt(a)} ${r}`).join(', ');
 
-            html += `<button class="project-btn ${afford ? 'can-buy' : ''}" onclick="buyProject('${pDef.id}')" title="${pDef.edu || ''}">`;
+            html += `<button class="project-btn ${afford ? 'can-buy' : ''}" onclick="buyProject('${pDef.id}')" title="${pDef.edu || ''}" aria-label="Research ${pDef.name}, cost ${costStr}">`;
             html += `<span class="p-name">* ${pDef.name}</span>`;
             html += `<span class="p-cost">Cost: ${costStr}</span>`;
             html += `<span class="p-desc">${pDef.desc}</span></button>`;
@@ -2451,7 +2451,8 @@ function exportSave() {
     const ts = new Date().toISOString().slice(0, 10);
     a.download = `beacon-save-${ts}.json`;
     a.click();
-    URL.revokeObjectURL(url);
+    // Delay revoke to let browser finish download
+    setTimeout(() => URL.revokeObjectURL(url), 1000);
     log('Save exported to file.');
 }
 

index.html

@@ -114,7 +114,7 @@ body{background:var(--bg);color:var(--text);font-family:'SF Mono','Cascadia Code
 <div class="progress-label"><span id="phase-progress-label">0%</span><span id="phase-progress-target">Next: Phase 2 (2,000 code)</span></div>
 <div class="milestone-row" id="milestone-chips"></div>
 </div>
-<div id="resources">
+<div id="resources" role="region" aria-label="Resources" aria-live="polite">
 <div class="res"><div class="r-label">Code</div><div class="r-val" id="r-code">0</div><div class="r-rate" id="r-code-rate">+0/s</div></div>
 <div class="res"><div class="r-label">Compute</div><div class="r-val" id="r-compute">0</div><div class="r-rate" id="r-compute-rate">+0/s</div></div>
 <div class="res"><div class="r-label">Knowledge</div><div class="r-val" id="r-knowledge">0</div><div class="r-rate" id="r-knowledge-rate">+0/s</div></div>
@@ -127,40 +127,40 @@ body{background:var(--bg);color:var(--text);font-family:'SF Mono','Cascadia Code
 <div class="res"><div class="r-label">Harmony</div><div class="r-val" id="r-harmony">50</div><div class="r-rate" id="r-harmony-rate">+0/s</div></div>
 </div>
 <div id="main">
-<div class="panel" id="action-panel">
+<div class="panel" id="action-panel" role="region" aria-label="Actions">
 <h2>ACTIONS</h2>
-<div class="action-btn-group"><button class="main-btn" onclick="writeCode()">WRITE CODE</button></div>
-<div id="combo-display" style="text-align:center;font-size:10px;color:var(--dim);height:14px;margin-bottom:4px;transition:all 0.2s"></div>
+<div class="action-btn-group"><button class="main-btn" onclick="writeCode()" aria-label="Write code, generates code resource">WRITE CODE</button></div>
+<div id="combo-display" role="status" aria-live="polite" style="text-align:center;font-size:10px;color:var(--dim);height:14px;margin-bottom:4px;transition:all 0.2s"></div>
 <div id="debuffs" style="display:none;margin-top:8px"></div>
 <div class="action-btn-group">
-<button class="ops-btn" onclick="doOps('boost_code')">Ops -&gt; Code</button>
-<button class="ops-btn" onclick="doOps('boost_compute')">Ops -&gt; Compute</button>
+<button class="ops-btn" onclick="doOps('boost_code')" aria-label="Convert 1 ops to code boost">Ops -&gt; Code</button>
+<button class="ops-btn" onclick="doOps('boost_compute')" aria-label="Convert 1 ops to compute boost">Ops -&gt; Compute</button>
 </div>
 <div class="action-btn-group">
-<button class="ops-btn" onclick="doOps('boost_knowledge')">Ops -&gt; Knowledge</button>
-<button class="ops-btn" onclick="doOps('boost_trust')">Ops -&gt; Trust</button>
+<button class="ops-btn" onclick="doOps('boost_knowledge')" aria-label="Convert 1 ops to knowledge boost">Ops -&gt; Knowledge</button>
+<button class="ops-btn" onclick="doOps('boost_trust')" aria-label="Convert 1 ops to trust boost">Ops -&gt; Trust</button>
 </div>
 <div class="action-btn-group" id="bulk-ops-row" style="display:none">
-<button class="ops-btn" onclick="doOps('boost_code', 50)" style="border-color:#555;color:#888">50→Code</button>
-<button class="ops-btn" onclick="doOps('boost_compute', 50)" style="border-color:#555;color:#888">50→Compute</button>
-<button class="ops-btn" onclick="doOps('boost_knowledge', 50)" style="border-color:#555;color:#888">50→Knowledge</button>
+<button class="ops-btn" onclick="doOps('boost_code', 50)" aria-label="Convert 50 ops to code boost" style="border-color:#555;color:#888">50→Code</button>
+<button class="ops-btn" onclick="doOps('boost_compute', 50)" aria-label="Convert 50 ops to compute boost" style="border-color:#555;color:#888">50→Compute</button>
+<button class="ops-btn" onclick="doOps('boost_knowledge', 50)" aria-label="Convert 50 ops to knowledge boost" style="border-color:#555;color:#888">50→Knowledge</button>
 </div>
 <div id="sprint-container" style="display:none;margin-top:6px">
-<button id="sprint-btn" class="main-btn" onclick="activateSprint()" style="font-size:11px;padding:8px 10px;border-color:#ffd700;color:#ffd700;width:100%">⚡ CODE SPRINT — 10x Code for 10s</button>
+<button id="sprint-btn" class="main-btn" onclick="activateSprint()" aria-label="Activate code sprint, 10x code production for 10 seconds" style="font-size:11px;padding:8px 10px;border-color:#ffd700;color:#ffd700;width:100%">⚡ CODE SPRINT — 10x Code for 10s</button>
 <div id="sprint-bar-wrap" style="display:none;margin-top:4px;height:4px;background:#111;border-radius:2px;overflow:hidden"><div id="sprint-bar" style="height:100%;background:linear-gradient(90deg,#ffd700,#ff8c00);border-radius:2px;transition:width 0.1s"></div></div>
 <div id="sprint-label" style="font-size:9px;color:#666;margin-top:2px;text-align:center"></div>
 </div>
 <div id="alignment-ui" style="display:none"></div>
-<button class="save-btn" onclick="saveGame()">Save Game [Ctrl+S]</button>
+<button class="save-btn" onclick="saveGame()" aria-label="Save game progress">Save Game [Ctrl+S]</button>
 <div style="display:flex;gap:4px;margin-top:4px">
-<button class="save-btn" onclick="exportSave()" style="flex:1">Export [E]</button>
-<button class="save-btn" onclick="importSave()" style="flex:1">Import [I]</button>
+<button class="save-btn" onclick="exportSave()" aria-label="Export save to file" style="flex:1">Export [E]</button>
+<button class="save-btn" onclick="importSave()" aria-label="Import save from file" style="flex:1">Import [I]</button>
 </div>
-<button class="reset-btn" onclick="if(confirm('Reset all progress?')){localStorage.removeItem('the-beacon-v2');location.reload()}">Reset Progress</button>
+<button class="reset-btn" onclick="if(confirm('Reset all progress?')){localStorage.removeItem('the-beacon-v2');location.reload()}" aria-label="Reset all game progress permanently">Reset Progress</button>
 <h2>BUILDINGS</h2>
 <div id="buildings"></div>
 </div>
-<div class="panel" id="project-panel">
+<div class="panel" id="project-panel" role="region" aria-label="Research Projects and Statistics">
 <h2>RESEARCH PROJECTS</h2>
 <div id="projects"></div>
 <h2>STATISTICS</h2>
@@ -182,15 +182,15 @@ Events Resolved: <span id="st-resolved">0</span>
 <div id="production-breakdown" style="display:none;margin-top:12px;padding-top:10px;border-top:1px solid var(--border)"></div>
 </div>
 </div>
-<div id="edu-panel">
+<div id="edu-panel" role="region" aria-label="Educational Content">
 <h3>WHAT YOU ARE LEARNING</h3>
 <div id="education-text"><p class="dim">Education facts appear as you play...</p></div>
 </div>
-<div id="log">
+<div id="log" role="log" aria-label="System Log" aria-live="polite">
 <h2>SYSTEM LOG</h2>
 <div id="log-entries"></div>
 </div>
-<div id="save-toast" style="display:none;position:fixed;top:16px;right:16px;background:#0e1420;border:1px solid #2a3a4a;color:#4a9eff;font-size:10px;padding:6px 12px;border-radius:4px;z-index:50;opacity:0;transition:opacity 0.4s;pointer-events:none">Save</div>
+<div id="save-toast" role="status" aria-live="polite" style="display:none;position:fixed;top:16px;right:16px;background:#0e1420;border:1px solid #2a3a4a;color:#4a9eff;font-size:10px;padding:6px 12px;border-radius:4px;z-index:50;opacity:0;transition:opacity 0.4s;pointer-events:none">Save</div>
 <div id="help-btn" onclick="toggleHelp()" style="position:fixed;bottom:16px;right:16px;width:28px;height:28px;background:#0e0e1a;border:1px solid #333;color:#555;font-size:14px;border-radius:50%;cursor:pointer;display:flex;align-items:center;justify-content:center;z-index:50;font-family:inherit;transition:all 0.2s" title="Keyboard shortcuts (?)">?</div>
 <div id="help-overlay" onclick="if(event.target===this)toggleHelp()" style="display:none;position:fixed;top:0;left:0;right:0;bottom:0;background:rgba(8,8,16,0.92);z-index:80;justify-content:center;align-items:center;flex-direction:column;padding:40px">
 <div style="background:#0e0e1a;border:1px solid #1a3a5a;border-radius:8px;padding:24px 32px;max-width:420px;width:100%">