feat(server): implement KV store API and fingerprinting functionality

- Added a new KV store API with endpoints for querying namespaces and key-value pairs.
- Introduced fingerprinting functionality to hash and manage data fingerprints, allowing for efficient change detection.
- Enhanced existing scripts to utilize the new fingerprinting capabilities, enabling conditional execution based on data changes.
- Updated the web interface to include a dedicated KV page for managing key-value entries and displaying their details.
- Improved overall user experience with pagination and search capabilities in the KV management interface.

packages/web/src/pages/EventDetailPage.jsx

@@ -98,7 +98,7 @@ export function EventDetailPage() {
                 <th>Script</th>
                 <th>Status</th>
                 <th>Duration</th>
-                <th>Error</th>
+                <th>Detail</th>
                 <th></th>
               </tr>
             </thead>
@@ -119,7 +119,13 @@ export function EventDetailPage() {
                     <StatusBadge status={s.status} />
                   </td>
                   <td>{s.duration_ms != null ? `${s.duration_ms}ms` : "—"}</td>
-                  <td className="text-error text-xs">{s.error || ""}</td>
+                  <td
+                    className={
+                      s.status === "skipped" ? "opacity-60 text-xs" : "text-error text-xs"
+                    }
+                  >
+                    {s.error || ""}
+                  </td>
                   <td className="text-right">
                     <button
                       type="button"

packages/web/src/pages/KvPage.jsx

@@ -0,0 +1,143 @@
+import { useState } from "react";
+import { useSearchParams } from "react-router-dom";
+import { useKv, useKvNamespaces } from "../api/hooks.js";
+import { formatTime } from "../lib/format.jsx";
+
+const PAGE_SIZE = 50;
+
+function previewValue(value) {
+  const json = JSON.stringify(value);
+  if (json == null) return "—";
+  if (json.length <= 120) return json;
+  return `${json.slice(0, 120)}…`;
+}
+
+export function KvPage() {
+  const [params, setParams] = useSearchParams();
+  const namespace = params.get("namespace") || "";
+  const q = params.get("q") || "";
+  const offset = Math.max(Number(params.get("offset")) || 0, 0);
+  const [expanded, setExpanded] = useState(null);
+
+  const { data: namespaces = [] } = useKvNamespaces();
+  const { data, isLoading } = useKv({
+    namespace: namespace || undefined,
+    q: q || undefined,
+    limit: PAGE_SIZE,
+    offset,
+  });
+
+  const items = data?.items ?? [];
+  const total = data?.total ?? 0;
+  const limit = data?.limit ?? PAGE_SIZE;
+
+  function update(key, value, resetOffset = true) {
+    const next = new URLSearchParams(params);
+    if (value) next.set(key, value);
+    else next.delete(key);
+    if (resetOffset && key !== "offset") next.delete("offset");
+    setParams(next);
+    setExpanded(null);
+  }
+
+  function rowId(item) {
+    return `${item.namespace}\0${item.key}`;
+  }
+
+  return (
+    <div className="space-y-4">
+      <h1 className="text-xl font-semibold">KV</h1>
+      <div className="flex flex-col sm:flex-row gap-2">
+        <select
+          className="select select-sm w-full sm:max-w-xs"
+          value={namespace}
+          onChange={(e) => update("namespace", e.target.value)}
+        >
+          <option value="">all namespaces</option>
+          {namespaces.map((ns) => (
+            <option key={ns} value={ns}>
+              {ns}
+            </option>
+          ))}
+        </select>
+        <input
+          className="input input-sm w-full sm:max-w-sm"
+          placeholder="search key or value"
+          value={q}
+          onChange={(e) => update("q", e.target.value)}
+        />
+      </div>
+      {isLoading ? (
+        <span className="loading loading-spinner" />
+      ) : items.length === 0 ? (
+        <p className="text-sm opacity-60">No KV entries.</p>
+      ) : (
+        <>
+          <div className="overflow-x-auto">
+            <table className="table table-sm">
+              <thead>
+                <tr>
+                  <th>Namespace</th>
+                  <th>Key</th>
+                  <th>Value</th>
+                  <th>Updated</th>
+                  <th>Expires</th>
+                </tr>
+              </thead>
+              <tbody>
+                {items.map((item) => {
+                  const id = rowId(item);
+                  const open = expanded === id;
+                  return (
+                    <tr
+                      key={id}
+                      className="hover cursor-pointer"
+                      onClick={() => setExpanded(open ? null : id)}
+                    >
+                      <td className="font-mono text-xs align-top">{item.namespace}</td>
+                      <td className="font-mono text-xs align-top">{item.key}</td>
+                      <td className="align-top">
+                        {open ? (
+                          <pre className="text-xs whitespace-pre-wrap break-all max-w-xl">
+                            {JSON.stringify(item.value, null, 2)}
+                          </pre>
+                        ) : (
+                          <span className="font-mono text-xs">{previewValue(item.value)}</span>
+                        )}
+                      </td>
+                      <td className="whitespace-nowrap align-top">{formatTime(item.updatedAt)}</td>
+                      <td className="whitespace-nowrap align-top">
+                        {item.expiresAt ? formatTime(item.expiresAt) : "—"}
+                      </td>
+                    </tr>
+                  );
+                })}
+              </tbody>
+            </table>
+          </div>
+          <div className="flex items-center gap-2 text-sm">
+            <button
+              type="button"
+              className="btn btn-sm"
+              disabled={offset <= 0}
+              onClick={() => update("offset", String(Math.max(offset - limit, 0)), false)}
+            >
+              Prev
+            </button>
+            <button
+              type="button"
+              className="btn btn-sm"
+              disabled={offset + items.length >= total}
+              onClick={() => update("offset", String(offset + limit), false)}
+            >
+              Next
+            </button>
+            <span className="opacity-60">
+              {total === 0 ? "0" : `${offset + 1}–${offset + items.length}`} of {total}
+            </span>
+          </div>
+        </>
+      )}
+    </div>
+  );
+}