fix(dashboard): write ChatView visualViewport vars imperatively

The mobile composer/footer slid over the message list when the user
swiped with the keyboard up. Cause: --vv-height / --vv-offset-top were
routed through React state via useMobileKeyboard, so on iOS — which
fires visualViewport scroll/resize on the same frame as its keyboard
animation — the .chat-thread translation lagged by one paint, visible
as the composer momentarily floating over messages.

Now those two vars are written imperatively in a useLayoutEffect
directly to the .chat-thread DOM node on every visualViewport event,
mirroring the working pattern at QuickChatFAB.tsx:1032-1052 (which
already works correctly on mobile). Only --keyboard-overlap (a
structural open/close signal, not per-frame) still flows through
React state.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

plugins/fusion-plugin-hermes-runtime/dist/probe.d.ts

@@ -0,0 +1,35 @@
+/**
+ * Hermes binary probe helper.
+ *
+ * Mirrors the probeClaudeCli pattern from packages/dashboard/src/claude-cli-probe.ts.
+ * Never throws — all failures are captured as `available: false` with a reason.
+ */
+/**
+ * Result of probing for the hermes binary.
+ */
+export interface HermesBinaryStatus {
+    /** True if the binary was found and ran to completion successfully. */
+    available: boolean;
+    /** Absolute path resolved via `which`/`where`, if found. */
+    binaryPath?: string;
+    /** Version string from `hermes --version` stdout, if available. */
+    version?: string;
+    /** Human-readable failure reason when `available === false`. */
+    reason?: string;
+    /** Wall-clock duration of the probe in milliseconds. */
+    probeDurationMs: number;
+}
+/**
+ * Probe for the hermes binary.
+ *
+ * Runs `<binaryPath> --version` with a short timeout. Use this from
+ * the dashboard status endpoint to check binary presence without crashing.
+ *
+ * @param opts.binaryPath - Override the binary path (default: "hermes").
+ * @param opts.timeoutMs  - Override probe timeout in ms (default: 2000).
+ */
+export declare function probeHermesBinary(opts?: {
+    binaryPath?: string;
+    timeoutMs?: number;
+}): Promise<HermesBinaryStatus>;
+//# sourceMappingURL=probe.d.ts.map