Extensions: hub bridge for tasks, contacts and calendar (asked of the person once), Sites in My Store, and four example extensions

- hub.tasks / hub.contacts / hub.calendar in the extension sandbox; each kind of access is approved by the person and remembered per extension
- My Store: Sites kind (any web link, optionally shown inside the hub)
- Examples: notes and checklists, habit tracker, kitchen converter and scaler, weather and verse of the day

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

docs/extensions/kitchen.html

@@ -0,0 +1,32 @@
+<!doctype html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width,initial-scale=1"><title>Kitchen</title>
+<style>
+:root{--bg:#fff;--fg:#1b1e24;--mut:#6b7280;--line:#e0e3e9;--acc:#e0742b;--card:#f4f5f8}@media(prefers-color-scheme:dark){:root{--bg:#181b21;--fg:#eceef2;--mut:#8b93a3;--line:#2a2f38;--acc:#f0883e;--card:#20242c}}
+*{box-sizing:border-box}body{margin:0;padding:14px;font:15px system-ui,sans-serif;background:var(--bg);color:var(--fg);max-width:720px}h2{margin:18px 0 8px}h2:first-child{margin-top:0}
+input,select,textarea,button{font:inherit;color:inherit;background:var(--card);border:1px solid var(--line);border-radius:8px;padding:8px}button{cursor:pointer}button.p{background:var(--acc);color:#fff;border-color:var(--acc)}
+.r{display:flex;gap:8px;align-items:center;flex-wrap:wrap;margin:6px 0}textarea{width:100%;height:150px}pre{background:var(--card);border-radius:8px;padding:10px;white-space:pre-wrap;margin:8px 0}.m{color:var(--mut);font-size:13px}
+</style></head><body>
+<h2>Convert</h2>
+<div class="r"><input id="v" type="number" step="any" value="1" style="width:110px"><select id="from"></select><span>to</span><select id="to"></select></div><div id="out" style="font-size:22px;font-weight:600"></div>
+<h2>Scale a recipe</h2>
+<div class="r"><span>From</span><input id="a" type="number" min="1" value="4" style="width:70px"><span>servings to</span><input id="b" type="number" min="1" value="6" style="width:70px"></div>
+<textarea id="t" placeholder="Paste ingredients, one per line&#10;2 cups flour&#10;1 1/2 tsp salt&#10;3/4 cup sugar"></textarea>
+<div class="r"><button class="p" id="go">Scale</button><button id="sl" disabled>Add to my Shopping list</button></div><pre id="res" hidden></pre><div class="m" id="msg"></div>
+<script>
+var U={cup:['Volume',236.588],tbsp:['Volume',14.787],tsp:['Volume',4.929],ml:['Volume',1],l:['Volume',1000],'fl oz':['Volume',29.574],pint:['Volume',473.176],quart:['Volume',946.353],
+g:['Weight',1],kg:['Weight',1000],oz:['Weight',28.3495],lb:['Weight',453.592]};
+var opts=Object.keys(U).map(function(k){return '<option>'+k+'</option>'}).join('')+'<option>F</option><option>C</option>';
+from.innerHTML=opts;to.innerHTML=opts;from.value='cup';to.value='ml';
+function conv(){var x=parseFloat(v.value),f=from.value,t=to.value,o;if(isNaN(x)){out.textContent='';return}
+if((f==='F'||f==='C')&&(t==='F'||t==='C'))o=f===t?x:f==='F'?(x-32)*5/9:x*9/5+32;
+else if(U[f]&&U[t]&&U[f][0]===U[t][0])o=x*U[f][1]/U[t][1];else{out.textContent='Cannot convert '+(U[f]?U[f][0]:'temperature')+' to '+(U[t]?U[t][0]:'temperature').toLowerCase();return}
+out.textContent=x+' '+f+' = '+(Math.round(o*100)/100)+' '+t}
+[v,from,to].forEach(function(e){e.oninput=conv});conv();
+var FR={'½':.5,'¼':.25,'¾':.75,'⅓':1/3,'⅔':2/3,'⅛':.125};
+function num(s){s=s.trim();var m;if((m=/^(\d+)\s+(\d+)\/(\d+)$/.exec(s)))return +m[1]+m[2]/m[3];if((m=/^(\d+)\/(\d+)$/.exec(s)))return m[1]/m[2];if((m=/^(\d*)\s*([½¼¾⅓⅔⅛])$/.exec(s)))return (+m[1]||0)+FR[m[2]];return /^\d*\.?\d+$/.test(s)?parseFloat(s):null}
+function show(n){var w=Math.floor(n+1e-9),f=n-w,names=[[0,''],[.125,'1/8'],[.25,'1/4'],[1/3,'1/3'],[.5,'1/2'],[2/3,'2/3'],[.75,'3/4'],[1,'']],best=names[0];names.forEach(function(c){if(Math.abs(c[0]-f)<Math.abs(best[0]-f))best=c});
+if(Math.abs(best[0]-f)>0.04)return String(Math.round(n*100)/100);if(best[0]===1){w++;best=names[0]}return (w?w+(best[1]?' ':''):'')+best[1]||'0'}
+var lines=[];
+go.onclick=function(){var k=(+b.value)/(+a.value);if(!(k>0))return;lines=t.value.split('\n').map(function(l){return l.trim()}).filter(Boolean).map(function(l){var m=/^((?:\d+\s+)?\d+\/\d+|\d*\s*[½¼¾⅓⅔⅛]|\d*\.?\d+)(.*)$/.exec(l);if(!m)return l;var n=num(m[1]);return n==null?l:show(n*k)+m[2]});
+res.hidden=false;res.textContent=lines.join('\n');sl.disabled=!lines.length;msg.textContent='Scaled by '+(Math.round(k*100)/100)+'x'};
+sl.onclick=function(){sl.disabled=true;(function next(i){if(i>=lines.length){hub.toast('Added '+lines.length+' items to Shopping');sl.disabled=false;return}hub.tasks.add({list:'Shopping',title:lines[i]}).then(function(){next(i+1)},function(e){hub.toast(e.message);sl.disabled=false})})(0)};
+</script></body></html>