capsite/diigo-cache: the wire page hands the owner the store id

webapp's mint now answers a store id (x-webapp-store-id) beside the
instance id: authority to rotate or revoke the diigo cookie. The wire
page shows it apart from the instance id, with its own copy button,
petname, and password-manager save; the cache never gets it. A webapp
that sends none gets a note on the page and a warning in the log.

Generated-by: Claude Opus 5.5

diigo-cache/src/index.ts

@@ -174,11 +174,13 @@ async function proxyMint(request: Request, env: Env): Promise<Response> {
 			const detail = (await res.text()).slice(0, 200);
 			return home(env, { error: `mint said ${res.status}: ${detail}` }, null);
 		}
-		// webapp answers {id} (+ x-webapp-id); the id rides the header, the
+		// webapp answers {id, storeId} (+ x-webapp-id, x-webapp-store-id);
-		// wire page is ours
+		// the ids ride the headers, the wire page is ours
 		const id = res.headers.get("x-webapp-id");
 		if (!id) return home(env, { error: "mint produced no id" }, null);
-		return await wirePage(id);
+		const storeId = res.headers.get("x-webapp-store-id");
+		if (!storeId) console.warn({ event: "mint", outcome: "no store id: this session cannot be rotated" });
+		return await wirePage(id, storeId);
 	} catch (err) {
 		console.error({ event: "mint", error: String(err) });
 		return home(env, { error: `mint failed: ${String(err)}` }, null);
@@ -188,22 +190,37 @@ async function proxyMint(request: Request, env: Env): Promise<Response> {
 /** the credential-save helper, once per page (see ./pm-save.ts) */
 const PM_SAVE_JS = pmSave.toString();
 
-/** the suggested petname gets the holder's local hh:mm (the worker only
+/** the suggested petname (in the input with id `petnameId`) gets the
- * knows UTC), so two saves the same day are told apart at a glance */
+ * holder's local hh:mm (the worker only knows UTC), so two saves the same
-const PETNAME_TIME_JS = `{
+ * day are told apart at a glance */
-	const p = document.getElementById("petname");
+function petnameTimeJs(petnameId: string): string {
+	return `{
+	const p = document.getElementById(${JSON.stringify(petnameId)});
 	const d = new Date();
 	p.value += " " + String(d.getHours()).padStart(2, "0") + ":" + String(d.getMinutes()).padStart(2, "0");
 }`;
-
-/** the onclick that hands pmSave its browser powers */
-function pmSaveClick(value: string): string {
-	return `pmSave(this, ${JSON.stringify(value)}, { petname: document.getElementById("petname"), credentials: navigator.credentials, PasswordCredential: window.PasswordCredential, log: console })`;
 }
 
-/** the wire step, with the freshly-minted webapp id pre-filled */
+/** the onclick that hands pmSave its browser powers, saving under the
-async function wirePage(webappId: string): Promise<Response> {
+ * petname in the input with id `petnameId` */
+function pmSaveClick(value: string, petnameId: string): string {
+	return `pmSave(this, ${JSON.stringify(value)}, { petname: document.getElementById(${JSON.stringify(petnameId)}), credentials: navigator.credentials, PasswordCredential: window.PasswordCredential, log: console })`;
+}
+
+/** the wire step, with the freshly-minted webapp id pre-filled, and the
+ * store id (rotating the cookie) for the account owner to keep */
+async function wirePage(webappId: string, storeId: string | null): Promise<Response> {
 	const fingerprint = await nick(webappId);
+	const storeSection = storeId
+		? `<h2>keep: the cookie's store id</h2>
+<p>This one is yours alone, not the cache's: with it you can rotate the
+diigo session (log in again, paste the new cookie) or revoke it. Fingerprint
+<code>${esc(await nick(storeId))}</code>
+<button type="button" onclick='navigator.clipboard.writeText(${JSON.stringify(storeId)}).then(() => this.textContent = "copied ✓")'>copy</button></p>
+<p><label>your petname for it <input id="store-petname" autocomplete="off" size="30" value="${esc(`diigo cookie store ${await nick(storeId)}`)}"></label></p>
+<script>${petnameTimeJs("store-petname")}</script>
+<p><button type="button" onclick='${pmSaveClick(storeId, "store-petname")}'>save to password manager</button></p>`
+		: `<p><b>note:</b> webapp sent no store id, so this session's cookie cannot be rotated; when it expires, mint again.</p>`;
 	const body = `<!doctype html>
 <html><head><meta charset="utf-8"><title>diigo cache: step 2 — wire the cache</title></head>
 <body>
@@ -212,8 +229,10 @@ async function wirePage(webappId: string): Promise<Response> {
 <button type="button" onclick='navigator.clipboard.writeText(${JSON.stringify(webappId)}).then(() => this.textContent = "copied ✓")'>copy</button></p>
 <p><label>your petname for it <input id="petname" autocomplete="off" size="30" value="${esc(`diigo webapp ${fingerprint}`)}"></label>
 <small>(private to you: the password-manager username; never sent to the server)</small></p>
-<script>${PETNAME_TIME_JS}</script>
+<script>${petnameTimeJs("petname")}</script>
-<p><button type="button" onclick='${pmSaveClick(webappId)}'>save to password manager</button></p>
+<p><button type="button" onclick='${pmSaveClick(webappId, "petname")}'>save to password manager</button></p>
+${storeSection}
+<h2>wire</h2>
 <p>choose the cache mode, then <b>wire</b> — the next page shows the
 <b>cache id</b> (copy that too), after which you land back on home:</p>
 <form method="post" action="/_wire">
@@ -320,8 +339,8 @@ async function wiredPage(cacheId: string, note: string, hasPublic: boolean): Pro
 <button type="button" onclick='navigator.clipboard.writeText(${JSON.stringify(cacheId)}).then(() => this.textContent = "copied ✓")'>copy</button></p>
 <p><label>your petname for it <input id="petname" autocomplete="off" size="30" value="${esc(`diigo cache ${fingerprint}`)}"></label>
 <small>(private to you: the password-manager username; never sent to the server)</small></p>
-<script>${PETNAME_TIME_JS}</script>
+<script>${petnameTimeJs("petname")}</script>
-<p><button type="button" onclick='${pmSaveClick(cacheId)}'>save to password manager</button></p>
+<p><button type="button" onclick='${pmSaveClick(cacheId, "petname")}'>save to password manager</button></p>
 <p>${note}</p>
 <p><a href="/cache/#${esc(cacheId)}">open this cache</a> — its <b>webkey</b>
 (bookmark it, or save the id above): fill it, watch progress${hasPublic ? ", fill its public companion" : ""}.</p>