feat: improve usability with clickable keyboard hints

This allows people to use the app even if they aren't used to their
keyboard.
Closes #186

js/desktop/src/stores/compose-intent-store.ts

@@ -0,0 +1,34 @@
+import { create } from "zustand";
+
+/**
+ * Fire-and-forget intents that drive the compose flow from outside the active
+ * ComposeOverlay (e.g. clickable keyboard hints in the bottom controls or in
+ * the recording overlay). The active overlay subscribes to `intent`, runs the
+ * step-aware handler, then calls `clear()`.
+ *
+ * | intent | valid step      | effect                                     |
+ * |--------|-----------------|--------------------------------------------|
+ * | record | idle            | start a media (camera/mic) recording       |
+ * | text   | idle            | open the text compose step                 |
+ * | stop   | recording       | finish recording → review                  |
+ * | cancel | recording, etc. | abort recording / discard review           |
+ * | send   | reviewing       | submit the recorded particle               |
+ *
+ * Keyboard handlers stay local to ComposeOverlay (no round-trip), but they
+ * ultimately invoke the same callbacks the intent dispatcher does, so the
+ * guard logic stays in one place.
+ */
+export type ComposeIntent = "record" | "text" | "stop" | "cancel" | "send";
+
+interface ComposeIntentState {
+  intent: { kind: ComposeIntent } | null;
+  request: (kind: ComposeIntent) => void;
+  clear: () => void;
+}
+
+export const useComposeIntentStore = create<ComposeIntentState>((set) => ({
+  intent: null,
+  // New object each call — ensures useEffect refires for repeated same kind.
+  request: (kind) => set({ intent: { kind } }),
+  clear: () => set({ intent: null }),
+}));