Remove recordings feature, replay sessions directly, bump to 0.6.0

Recordings were just a thin named pointer over an already-captured
session's events, so the whole separate feature (recordings table, API
routes, pages, UI) is gone: any completed session can now be named and
replayed directly. Replaying no longer creates a session or duplicates
events of its own - it just bumps the source session's playCount/lastPlayedAt.

Also renames play_sessions/playSession(s) to sessions/session(s) throughout
the schema, queries, API routes, and UI for consistency, and updates the
README to match the new flow.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

lib/buttplug/types.ts

@@ -4,6 +4,8 @@
  * rows) never has to import the client library directly.
  */
 
+import type { DeviceCapabilities } from "@/lib/db/schema";
+
 export type NormalizedOutputType = "vibrate" | "rotate" | "linear";
 export type CommandType = NormalizedOutputType | "stop";
 
@@ -32,3 +34,18 @@ export interface CommandEvent {
   value: number;
   durationMs?: number;
 }
+
+/**
+ * A device that took part in a session, as needed to remap it onto a
+ * currently-connected device for replay. Computed live from that session's
+ * session_devices/devices rows - not a frozen snapshot.
+ */
+export interface ReplayDeviceSlot {
+  slotLabel: string;
+  recordedBleName: string;
+  deviceClass: string | null;
+  capabilities: DeviceCapabilities | null;
+  /** The session_devices.id this slot was captured from - lets the replay UI
+   *  map a chosen live device back to this slot's session_events. */
+  sourceSessionDeviceId: number;
+}