chore(lint): clear the semantic .tsx backlog

Hand fixes for the findings --fix cannot touch, mirroring the fixes
already applied on the fe-docs feature branch (same file, same shape)
so its eventual rebase resolves cleanly:

- restore the return the no-confusing-void-expression autofix ate in
  useAbsentSnapshot (typed S | undefined; hook call kept for hook-order
  stability, undefined returned explicitly);
- re-type DOM queries the no-unnecessary-type-assertion autofix broke:
  getByRole<HTMLButtonElement>(...) generics instead of the removed
  as-casts (the eslint program and the client tsconfig aggregate
  disagree about these casts; the generic form satisfies both);
- justified eslint-disable for the deliberate legacy paths: keyCode 229
  IME-composition detection, execCommand clipboard fallbacks, lib.dom
  clipboard optionality, and the any-typed Reflect.get/this probes in
  test fakes;
- drop the dead react/no-danger directive (eslint-plugin-react is not
  loaded, so the rule never applied) keeping its shiki rationale;
- delete the tautological 'Z' comparison and the renameTarget null
  check already implied by renameBlocked;
- css-module non-null assertions replaced by type widening
  (Button className, TAG_CLASS Record) per the established pattern;
- misc: max-len comment wraps, void generic drop in the deferred test
  helper, unused type imports, floating selectWorkspace promises voided,
  member-delimiter newlines in inline type literals.

packages/client/web-react/src/scoped-slots.tsx

@@ -200,7 +200,8 @@ function standardKit(
   scope: SlotScope,
   info: SessionMaybeProvideInfo | undefined,
 ): {
-  kit: InjectedProps; actions: object | undefined
+  kit: InjectedProps
+  actions: object | undefined
 } {
   const kit: InjectedProps = {
     useSessions: observableHook(host.sessions.list),
@@ -253,7 +254,9 @@ function standardKit(
  * composition point, one per scope branch).
  */
 function SessionEntry({ entry, ownerProps, info }: {
-  entry: StoredEntry; ownerProps: object; info: SessionProvideInfo
+  entry: StoredEntry
+  ownerProps: object
+  info: SessionProvideInfo
 }) {
   const host = useHost()
   const Comp = entry.component as FC<InjectedProps>
@@ -280,7 +283,9 @@ function RootEntry({ entry, ownerProps }: { entry: StoredEntry; ownerProps: obje
 }
 
 function StrictSessionEntry({ slotKey, entry, ownerProps }: {
-  slotKey: string; entry: StoredEntry; ownerProps: object
+  slotKey: string
+  entry: StoredEntry
+  ownerProps: object
 }) {
   const info = useSessionMaybeProvideInfo()
   if (info.sessionId === undefined) return null
@@ -292,7 +297,9 @@ function StrictSessionEntry({ slotKey, entry, ownerProps }: {
 }
 
 function SlotOutlet({ slotKey, ownerProps, opts }: {
-  slotKey: string; ownerProps: object; opts?: (RenderOpts & ChainRenderOpts) | undefined
+  slotKey: string
+  ownerProps: object
+  opts?: (RenderOpts & ChainRenderOpts) | undefined
 }) {
   const host = useHost()
   // Version tick drives entries() re-read; the host batches per microtask.
@@ -335,7 +342,7 @@ function SlotOutlet({ slotKey, ownerProps, opts }: {
     return guarded(entry)
   }
   if (spec.kind === 'keyed') {
-    const entry = entries.find(e => e.options?.key === opts?.entryKey)
+    const entry = entries.find(e => e.options.key === opts?.entryKey)
     if (!entry) return <>{opts?.fallback ?? null}</>
     return guarded(entry)
   }
@@ -390,8 +397,8 @@ function SlotOutlet({ slotKey, ownerProps, opts }: {
   // list: registration order refined by explicit order, optional id filter.
   const withListOptions = entries.map(entry => ({
     entry,
-    id: entry.options?.id,
-    order: entry.options?.order ?? 0,
+    id: entry.options.id,
+    order: entry.options.order ?? 0,
   }))
   let list = [...withListOptions].sort((a, b) => a.order - b.order)
   if (opts?.only !== undefined) list = list.filter(item => item.id === opts.only)

packages/client/web-react/src/session-provider.tsx

@@ -77,7 +77,10 @@ export function maybeObservableHook<T>(source: HostObservable<T> | undefined): M
 }
 
 function useAbsentSnapshot<S>(_selector: (snapshot: never) => S, _equal?: (a: S, b: S) => boolean): S | undefined {
+  // The uSES subscription must still run (hook-order stability); the absent
+  // source always snapshots undefined, returned explicitly.
   observableHook(absentSource)(() => undefined)
+  return undefined
 }
 
 /**