feat: implement cross-device deduplication for Obsidian connectors using vault fingerprinting and enhance connector management

surfsense_obsidian/src/vault-identity.ts

@@ -0,0 +1,43 @@
+import type { App } from "obsidian";
+
+/**
+ * Deterministic SHA-256 over the vault name + sorted markdown paths.
+ *
+ * Two devices observing the same vault content compute the same value,
+ * regardless of how it was synced (iCloud, Syncthing, Obsidian Sync, …).
+ * The server uses this as the cross-device dedup key on /connect.
+ */
+export async function computeVaultFingerprint(app: App): Promise<string> {
+	const vaultName = app.vault.getName();
+	const paths = app.vault
+		.getMarkdownFiles()
+		.map((f) => f.path)
+		.sort();
+	const payload = `${vaultName}\n${paths.join("\n")}`;
+	const bytes = new TextEncoder().encode(payload);
+	const digest = await crypto.subtle.digest("SHA-256", bytes);
+	return bufferToHex(digest);
+}
+
+function bufferToHex(buf: ArrayBuffer): string {
+	const view = new Uint8Array(buf);
+	let hex = "";
+	for (let i = 0; i < view.length; i++) {
+		hex += (view[i] ?? 0).toString(16).padStart(2, "0");
+	}
+	return hex;
+}
+
+export function generateVaultUuid(): string {
+	const c = globalThis.crypto;
+	if (c?.randomUUID) return c.randomUUID();
+	const buf = new Uint8Array(16);
+	c.getRandomValues(buf);
+	buf[6] = ((buf[6] ?? 0) & 0x0f) | 0x40;
+	buf[8] = ((buf[8] ?? 0) & 0x3f) | 0x80;
+	const hex = Array.from(buf, (b) => b.toString(16).padStart(2, "0")).join("");
+	return `${hex.slice(0, 8)}-${hex.slice(8, 12)}-${hex.slice(12, 16)}-${hex.slice(
+		16,
+		20,
+	)}-${hex.slice(20)}`;
+}