Fix component bugs across hooks, elements, form, layout, editors and utils

- Hooks: per-instance timers in useReady; cleanup for useIntersectionObserver;
  useWebSocket no longer reconnects after unmount/refresh, drains the queue
  and dispatches non-JSON messages
- Modal/Popover/Dropdown: onClose only on close, Escape to close, no stray
  DOM props, hooks before early return, scrollbar-aware positioning,
  top-left/top-right dropdown positions
- Elements: Toast/Search/StarRating per-instance timers, Pagination labels
  and empty state, Breadcrumbs titles, LinkList dividers/props, segment-wise
  active-link matching (new utils/link-matches-path), Table object cells
- Form: Select with a default option is changeable, Input clear notifies
  controlled parents and copy works on textareas, Checkbox random label,
  NumberInputButtons runaway interval, upload prop/spread fixes
- Layout: Button disabled while loading, Stack gap and Span truncate via
  inline styles, Img fallbackImageSrc, className/JSDoc fixes
- Editors/MDX/AI: TinyMCE id/cleanup/stale handler/duplicate scripts,
  AceEditor debounce, markdown heights and frontmatter regex, last
  assistant message, AIPromptBlock prompt ref
- Utils: fetchApi headers/FormData/fetchOptions/no mutation, base64 file
  names and read errors, slugify underscore trim, serializeQuery zero values
- Tests for fetchApi, link matching, slugify and serializeQuery
- AGENTS.md updated for the package layout

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/utils/link-matches-path.ts

@@ -0,0 +1,45 @@
+type Params = {
+    href: string;
+    pathname: string;
+    /** Only match the exact path, not its sub-paths */
+    strict?: boolean;
+};
+
+function normalizePath(path: string) {
+    const trimmed = path.replace(/\/+$/, "");
+    return trimmed || "/";
+}
+
+/**
+ * # Check whether a link points to the current page
+ * A non-strict link matches its own path and any sub-path, segment-wise:
+ * `/blog` matches `/blog` and `/blog/post`, but not `/blogging`. The root
+ * link `/` only ever matches `/`. Links to other origins never match.
+ */
+export default function twuiLinkMatchesPath({
+    href,
+    pathname,
+    strict,
+}: Params): boolean {
+    if (href.startsWith("#")) return false;
+
+    let linkPath: string;
+
+    try {
+        const origin =
+            typeof window !== "undefined"
+                ? window.location.origin
+                : "http://twui.local";
+        const url = new URL(href, origin);
+        if (url.origin !== origin) return false;
+        linkPath = normalizePath(url.pathname);
+    } catch {
+        return false;
+    }
+
+    const currentPath = normalizePath(pathname);
+
+    if (strict || linkPath === "/") return linkPath === currentPath;
+
+    return currentPath === linkPath || currentPath.startsWith(`${linkPath}/`);
+}