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/device-remap.ts

@@ -1,5 +1,4 @@
-import type { RecordingDeviceSlot } from "@/lib/db/schema";
-import type { ConnectedDeviceInfo } from "./types";
+import type { ConnectedDeviceInfo, ReplayDeviceSlot } from "./types";
 
 export interface DeviceRemapEntry {
   slotLabel: string;
@@ -8,14 +7,14 @@ export interface DeviceRemapEntry {
 }
 
 /**
- * Best-effort name match from a recording's saved device slots to the
+ * Best-effort name match from a session's device slots to the
  * currently-connected devices. Web Bluetooth exposes no stable hardware id
  * across sessions, so this is inherently approximate: two devices sharing an
  * identical advertised name are indistinguishable and must be disambiguated
  * manually in the remap UI - this isn't a bug, it's a hard BLE limitation.
  */
 export function autoMapDeviceSlots(
-  slots: RecordingDeviceSlot[],
+  slots: ReplayDeviceSlot[],
   connectedDevices: ConnectedDeviceInfo[],
 ): DeviceRemapEntry[] {
   const usedIndexes = new Set<number>();